

<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccruedExpenses" xlink:href="clh-20181231.xsd#AccruedExpenses" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccruedExpensesNarrativeDetails" xlink:href="clh-20181231.xsd#AccruedExpensesNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccruedExpensesScheduleOfAccruedExpensesDetails" xlink:href="clh-20181231.xsd#AccruedExpensesScheduleOfAccruedExpensesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccruedExpensesTables" xlink:href="clh-20181231.xsd#AccruedExpensesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLoss" xlink:href="clh-20181231.xsd#AccumulatedOtherComprehensiveLoss" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossComponentsOfAociDetails" xlink:href="clh-20181231.xsd#AccumulatedOtherComprehensiveLossComponentsOfAociDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossReclassificationOutOfAociDetails" xlink:href="clh-20181231.xsd#AccumulatedOtherComprehensiveLossReclassificationOutOfAociDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossTables" xlink:href="clh-20181231.xsd#AccumulatedOtherComprehensiveLossTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinations" xlink:href="clh-20181231.xsd#BusinessCombinations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinations2016AcquisitionsDetails" xlink:href="clh-20181231.xsd#BusinessCombinations2016AcquisitionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinations2016AcquisitionsNarrativeDetails" xlink:href="clh-20181231.xsd#BusinessCombinations2016AcquisitionsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinations2017AcquisitionsDetails" xlink:href="clh-20181231.xsd#BusinessCombinations2017AcquisitionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinations2018AcquisitionDetails" xlink:href="clh-20181231.xsd#BusinessCombinations2018AcquisitionDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinations2018AcquisitionsNarrativeDetails" xlink:href="clh-20181231.xsd#BusinessCombinations2018AcquisitionsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinationsTables" xlink:href="clh-20181231.xsd#BusinessCombinationsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilities" xlink:href="clh-20181231.xsd#ClosureAndPostClosureLiabilities" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilitiesAnticipatedPaymentsDetails" xlink:href="clh-20181231.xsd#ClosureAndPostClosureLiabilitiesAnticipatedPaymentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilitiesChangesInPostClosureLiabilitiesDetails" xlink:href="clh-20181231.xsd#ClosureAndPostClosureLiabilitiesChangesInPostClosureLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilitiesTables" xlink:href="clh-20181231.xsd#ClosureAndPostClosureLiabilitiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/CommitmentsAndContingencies" xlink:href="clh-20181231.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/CommitmentsAndContingenciesFederalStateAndProvincialEnforcementActionsDetails" xlink:href="clh-20181231.xsd#CommitmentsAndContingenciesFederalStateAndProvincialEnforcementActionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/CommitmentsAndContingenciesLeasesDetails" xlink:href="clh-20181231.xsd#CommitmentsAndContingenciesLeasesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/CommitmentsAndContingenciesLegalAndAdministrativeProceedingsDetails" xlink:href="clh-20181231.xsd#CommitmentsAndContingenciesLegalAndAdministrativeProceedingsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/CommitmentsAndContingenciesOtherContingenciesDetails" xlink:href="clh-20181231.xsd#CommitmentsAndContingenciesOtherContingenciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/CommitmentsAndContingenciesSuperfundProceedingsDetails" xlink:href="clh-20181231.xsd#CommitmentsAndContingenciesSuperfundProceedingsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/CommitmentsAndContingenciesTables" xlink:href="clh-20181231.xsd#CommitmentsAndContingenciesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedBalanceSheets" xlink:href="clh-20181231.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="clh-20181231.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="clh-20181231.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="clh-20181231.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedStatementsOfComprehensiveIncomeParenthetical" xlink:href="clh-20181231.xsd#ConsolidatedStatementsOfComprehensiveIncomeParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedStatementsOfOperations" xlink:href="clh-20181231.xsd#ConsolidatedStatementsOfOperations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedStatementsOfOperationsParenthetical" xlink:href="clh-20181231.xsd#ConsolidatedStatementsOfOperationsParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:href="clh-20181231.xsd#ConsolidatedStatementsOfStockholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedStatementsOfStockholdersEquityParenthetical" xlink:href="clh-20181231.xsd#ConsolidatedStatementsOfStockholdersEquityParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DispositionOfBusiness" xlink:href="clh-20181231.xsd#DispositionOfBusiness" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DispositionOfBusiness2016DispositionDetails" xlink:href="clh-20181231.xsd#DispositionOfBusiness2016DispositionDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DispositionOfBusiness2016DispositionNarrativeDetails" xlink:href="clh-20181231.xsd#DispositionOfBusiness2016DispositionNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DispositionOfBusiness2017DispositionNarrativeDetails" xlink:href="clh-20181231.xsd#DispositionOfBusiness2017DispositionNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DispositionOfBusiness2017DispositionsDetails" xlink:href="clh-20181231.xsd#DispositionOfBusiness2017DispositionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DispositionOfBusinessDispositionOfBusinessIncomeLossAttributableToTransformerServicesDetails" xlink:href="clh-20181231.xsd#DispositionOfBusinessDispositionOfBusinessIncomeLossAttributableToTransformerServicesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DispositionOfBusinessIncomeLossAttributableToCatalystServicesDetails" xlink:href="clh-20181231.xsd#DispositionOfBusinessIncomeLossAttributableToCatalystServicesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DispositionOfBusinessTables" xlink:href="clh-20181231.xsd#DispositionOfBusinessTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DocumentAndEntityInformation" xlink:href="clh-20181231.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/EarningsLossPerShare" xlink:href="clh-20181231.xsd#EarningsLossPerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/EarningsLossPerShareAntiDilutiveSecuritiesDetails" xlink:href="clh-20181231.xsd#EarningsLossPerShareAntiDilutiveSecuritiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/EarningsLossPerShareReconciliationOfBasicAndDilutedEarningsPerShareComputationsDetails" xlink:href="clh-20181231.xsd#EarningsLossPerShareReconciliationOfBasicAndDilutedEarningsPerShareComputationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/EarningsLossPerShareTables" xlink:href="clh-20181231.xsd#EarningsLossPerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/FinancingArrangements" xlink:href="clh-20181231.xsd#FinancingArrangements" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/FinancingArrangementsNarrativeDetails" xlink:href="clh-20181231.xsd#FinancingArrangementsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/FinancingArrangementsSummaryOfFinancingArrangementsDetails" xlink:href="clh-20181231.xsd#FinancingArrangementsSummaryOfFinancingArrangementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/FinancingArrangementsTables" xlink:href="clh-20181231.xsd#FinancingArrangementsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssets" xlink:href="clh-20181231.xsd#GoodwillAndOtherIntangibleAssets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsChangesToGoodwillDetails" xlink:href="clh-20181231.xsd#GoodwillAndOtherIntangibleAssetsChangesToGoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsExpectedAmortizationDetails" xlink:href="clh-20181231.xsd#GoodwillAndOtherIntangibleAssetsExpectedAmortizationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsFiniteLivedAndIndefiniteLivedIntangibleAssetsDetails" xlink:href="clh-20181231.xsd#GoodwillAndOtherIntangibleAssetsFiniteLivedAndIndefiniteLivedIntangibleAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:href="clh-20181231.xsd#GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsTables" xlink:href="clh-20181231.xsd#GoodwillAndOtherIntangibleAssetsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiaries" xlink:href="clh-20181231.xsd#GuarantorAndNonGuarantorSubsidiaries" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesBalanceSheetDetails" xlink:href="clh-20181231.xsd#GuarantorAndNonGuarantorSubsidiariesBalanceSheetDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesCashFlowsDetails" xlink:href="clh-20181231.xsd#GuarantorAndNonGuarantorSubsidiariesCashFlowsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesIncomeStatementDetails" xlink:href="clh-20181231.xsd#GuarantorAndNonGuarantorSubsidiariesIncomeStatementDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesNarrativeDetails" xlink:href="clh-20181231.xsd#GuarantorAndNonGuarantorSubsidiariesNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesTables" xlink:href="clh-20181231.xsd#GuarantorAndNonGuarantorSubsidiariesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/IncomeTaxes" xlink:href="clh-20181231.xsd#IncomeTaxes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/IncomeTaxesAdditionalInformationDetails" xlink:href="clh-20181231.xsd#IncomeTaxesAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/IncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails" xlink:href="clh-20181231.xsd#IncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/IncomeTaxesProvisionForTaxExpenseDetails" xlink:href="clh-20181231.xsd#IncomeTaxesProvisionForTaxExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/IncomeTaxesTables" xlink:href="clh-20181231.xsd#IncomeTaxesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:href="clh-20181231.xsd#IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/InventoriesAndSupplies" xlink:href="clh-20181231.xsd#InventoriesAndSupplies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/InventoriesAndSuppliesDetails" xlink:href="clh-20181231.xsd#InventoriesAndSuppliesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/InventoriesAndSuppliesTables" xlink:href="clh-20181231.xsd#InventoriesAndSuppliesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/Operations" xlink:href="clh-20181231.xsd#Operations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/PropertyPlantAndEquipment" xlink:href="clh-20181231.xsd#PropertyPlantAndEquipment" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/PropertyPlantAndEquipmentDetails" xlink:href="clh-20181231.xsd#PropertyPlantAndEquipmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/PropertyPlantAndEquipmentTables" xlink:href="clh-20181231.xsd#PropertyPlantAndEquipmentTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/QuarterlyDataUnaudited" xlink:href="clh-20181231.xsd#QuarterlyDataUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/QuarterlyDataUnauditedDetails" xlink:href="clh-20181231.xsd#QuarterlyDataUnauditedDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/QuarterlyDataUnauditedTables" xlink:href="clh-20181231.xsd#QuarterlyDataUnauditedTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RemedialLiabilities" xlink:href="clh-20181231.xsd#RemedialLiabilities" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RemedialLiabilitiesAdditionalInformationDetails" xlink:href="clh-20181231.xsd#RemedialLiabilitiesAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RemedialLiabilitiesAnticipatedPaymentsDetails" xlink:href="clh-20181231.xsd#RemedialLiabilitiesAnticipatedPaymentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RemedialLiabilitiesChangesInRemedialLiabilitiesDetails" xlink:href="clh-20181231.xsd#RemedialLiabilitiesChangesInRemedialLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RemedialLiabilitiesEstimatesDetails" xlink:href="clh-20181231.xsd#RemedialLiabilitiesEstimatesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RemedialLiabilitiesTables" xlink:href="clh-20181231.xsd#RemedialLiabilitiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/Revenues" xlink:href="clh-20181231.xsd#Revenues" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RevenuesContractBalancesDetails" xlink:href="clh-20181231.xsd#RevenuesContractBalancesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RevenuesDisaggregationOfRevenueDetails" xlink:href="clh-20181231.xsd#RevenuesDisaggregationOfRevenueDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RevenuesNarrativeDetails" xlink:href="clh-20181231.xsd#RevenuesNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RevenuesTables" xlink:href="clh-20181231.xsd#RevenuesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ScheduleIiValuationAndQualifyingAccounts" xlink:href="clh-20181231.xsd#ScheduleIiValuationAndQualifyingAccounts" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ScheduleIiValuationAndQualifyingAccountsDetails" xlink:href="clh-20181231.xsd#ScheduleIiValuationAndQualifyingAccountsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReporting" xlink:href="clh-20181231.xsd#SegmentReporting" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingGeographicalInformationDetails" xlink:href="clh-20181231.xsd#SegmentReportingGeographicalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingSegmentAdditionalInformationDetails" xlink:href="clh-20181231.xsd#SegmentReportingSegmentAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingSegmentInformationRevenuesEbitaAndReconciliationToConsolidatedStatementOfOperationsDetails" xlink:href="clh-20181231.xsd#SegmentReportingSegmentInformationRevenuesEbitaAndReconciliationToConsolidatedStatementOfOperationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingTables" xlink:href="clh-20181231.xsd#SegmentReportingTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPolicies" xlink:href="clh-20181231.xsd#SignificantAccountingPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesAdvertisingExpenseDetails" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesAdvertisingExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesCashCashEquivalentsAndUncashedChecksDetails" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesCashCashEquivalentsAndUncashedChecksDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesCreditConcentrationDetails" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesCreditConcentrationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesGoodwillAndIntangibleAssetsDetails" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesGoodwillAndIntangibleAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesLandfillAccountingDetails" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesLandfillAccountingDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesMarketableSecuritiesAndCashEquivalentsDetails" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesMarketableSecuritiesAndCashEquivalentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesPolicies" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesPropertyPlantAndEquipmentDetails" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesPropertyPlantAndEquipmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesRecentAccountingPronouncementsDetails" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesRecentAccountingPronouncementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesRemedialLiabilitiesDetails" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesRemedialLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesTables" xlink:href="clh-20181231.xsd#SignificantAccountingPoliciesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlans" xlink:href="clh-20181231.xsd#StockBasedCompensationAndEmployeeBenefitPlans" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlansPerformanceStockAwardsDetails" xlink:href="clh-20181231.xsd#StockBasedCompensationAndEmployeeBenefitPlansPerformanceStockAwardsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlansRestrictedStockAwardsDetails" xlink:href="clh-20181231.xsd#StockBasedCompensationAndEmployeeBenefitPlansRestrictedStockAwardsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlansStockBasedCompensationDetails" xlink:href="clh-20181231.xsd#StockBasedCompensationAndEmployeeBenefitPlansStockBasedCompensationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlansTables" xlink:href="clh-20181231.xsd#StockBasedCompensationAndEmployeeBenefitPlansTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockholdersEquity" xlink:href="clh-20181231.xsd#StockholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockholdersEquityDetails" xlink:href="clh-20181231.xsd#StockholdersEquityDetails" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccruedExpenses" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccruedExpensesNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccruedExpensesScheduleOfAccruedExpensesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccruedExpensesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLoss" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossComponentsOfAociDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_808A2E429821C959FA8BDCA90E56F81D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_773442CFC181B966944DDCA90E11FABF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_808A2E429821C959FA8BDCA90E56F81D" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_773442CFC181B966944DDCA90E11FABF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_63814FDE287ECB11222BDCA90E124988" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_773442CFC181B966944DDCA90E11FABF" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_63814FDE287ECB11222BDCA90E124988" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_45DBD3625407D2EB36FEDCA90E12B68B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_63814FDE287ECB11222BDCA90E124988" xlink:to="loc_us-gaap_EquityComponentDomain_45DBD3625407D2EB36FEDCA90E12B68B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_45DBD3625407D2EB36FEDCA90E12B68B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_63814FDE287ECB11222BDCA90E124988" xlink:to="loc_us-gaap_EquityComponentDomain_45DBD3625407D2EB36FEDCA90E12B68B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_1B0F6343CDDECE2E4AE3DCA90E12B333" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_45DBD3625407D2EB36FEDCA90E12B68B" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_1B0F6343CDDECE2E4AE3DCA90E12B333" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_6069E89049199928E09ADCA90E55B96D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_45DBD3625407D2EB36FEDCA90E12B68B" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_6069E89049199928E09ADCA90E55B96D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_06D9CC55C87086FA861BDCA90E566E81" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_45DBD3625407D2EB36FEDCA90E12B68B" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_06D9CC55C87086FA861BDCA90E566E81" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_571480D149206D43D54DDCA90E56803D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_45DBD3625407D2EB36FEDCA90E12B68B" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_571480D149206D43D54DDCA90E56803D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_7A5E3056A9520A254C43DCA90E56B992" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_45DBD3625407D2EB36FEDCA90E12B68B" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_7A5E3056A9520A254C43DCA90E56B992" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5776A60CC083E4149280DCA90E566BAD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_808A2E429821C959FA8BDCA90E56F81D" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5776A60CC083E4149280DCA90E566BAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_298C59EC91C60D5E01A7DCA90E5756C9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5776A60CC083E4149280DCA90E566BAD" xlink:to="loc_us-gaap_StockholdersEquity_298C59EC91C60D5E01A7DCA90E5756C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent" xlink:label="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_8C4256D1B36D2BC999E1DCA90E57D44F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5776A60CC083E4149280DCA90E566BAD" xlink:to="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_8C4256D1B36D2BC999E1DCA90E57D44F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent_42744D0BC72C0B6D65BBDCA90E57D3D9" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5776A60CC083E4149280DCA90E566BAD" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent_42744D0BC72C0B6D65BBDCA90E57D3D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1_46CB8B54B59C91B0B1D5DCA90E5863B6" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5776A60CC083E4149280DCA90E566BAD" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1_46CB8B54B59C91B0B1D5DCA90E5863B6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_17BDDD02119F5900AD11DCA90E584490" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_5776A60CC083E4149280DCA90E566BAD" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_17BDDD02119F5900AD11DCA90E584490" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossReclassificationOutOfAociDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BusinessCombinations" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BusinessCombinations2016AcquisitionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_168FB5CCDCE0AE08A925F1BDC7FD17D2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_168FB5CCDCE0AE08A925F1BDC7FD17D2" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_E94A5BD2F6DF3B778DB2F1BDC7FD4D6A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_168FB5CCDCE0AE08A925F1BDC7FD17D2" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_E94A5BD2F6DF3B778DB2F1BDC7FD4D6A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D680541161B00D6B9074F1BDC7FD0EEA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_E94A5BD2F6DF3B778DB2F1BDC7FD4D6A" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D680541161B00D6B9074F1BDC7FD0EEA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D680541161B00D6B9074F1BDC7FD0EEA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_E94A5BD2F6DF3B778DB2F1BDC7FD4D6A" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D680541161B00D6B9074F1BDC7FD0EEA" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_A2016BusinessAcquisitionsMember" xlink:label="loc_clh_A2016BusinessAcquisitionsMember_D8C26175943BAC6D083DF1BDC7FD49AD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D680541161B00D6B9074F1BDC7FD0EEA" xlink:to="loc_clh_A2016BusinessAcquisitionsMember_D8C26175943BAC6D083DF1BDC7FD49AD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_3250AA6A1B5E272A60B0F1BDC7FE7B9F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_3250AA6A1B5E272A60B0F1BDC7FE7B9F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_5E045FA7B7C90CC0C5B3F1BDC7FE21A2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_5E045FA7B7C90CC0C5B3F1BDC7FE21A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_30F49BFC4EEE9D9A62E3F1BDC7FF5465" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_30F49BFC4EEE9D9A62E3F1BDC7FF5465" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_9ACF889CD97464D36069F1BDC7FF2AA4" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_9ACF889CD97464D36069F1BDC7FF2AA4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_F1AA16D7788B518110F4F1BDC7FFC83D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_F1AA16D7788B518110F4F1BDC7FFC83D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_3A538866E7A8EB58015DF1BDC8004067" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_3A538866E7A8EB58015DF1BDC8004067" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesClosureandPostClosureLiabilities" xlink:label="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesClosureandPostClosureLiabilities_B6AEFF5F0661FB71D076F1BDC80080B2" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesClosureandPostClosureLiabilities_B6AEFF5F0661FB71D076F1BDC80080B2" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedRemedialLiabilitiesExcludingCurrentPortion" xlink:label="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedRemedialLiabilitiesExcludingCurrentPortion_C8D48385061CB033B721F1BDC800CA67" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedRemedialLiabilitiesExcludingCurrentPortion_C8D48385061CB033B721F1BDC800CA67" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesDeferredTaxesUnrecognizedTaxBenefitsandOtherLongtermLiabilities" xlink:label="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesDeferredTaxesUnrecognizedTaxBenefitsandOtherLongtermLiabilities_9961648DE80C6FE22A63F1BDC801D3C2" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesDeferredTaxesUnrecognizedTaxBenefitsandOtherLongtermLiabilities_9961648DE80C6FE22A63F1BDC801D3C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_7C786C304B9C067D3780F1BDC801761F" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_7C786C304B9C067D3780F1BDC801761F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_196397977C58969745F4F1BDC8011471" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_Goodwill_196397977C58969745F4F1BDC8011471" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_F96FA53B7973DD6053EFF1BDC8015276" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C1174E046846A0257A1EF1BDC7FEADE8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_F96FA53B7973DD6053EFF1BDC8015276" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BusinessCombinations2016AcquisitionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_D5A8D39C0633F5B7813D2D43188A43F2" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_65361BE57155CB056FCC2D43188928DC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D5A8D39C0633F5B7813D2D43188A43F2" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_65361BE57155CB056FCC2D43188928DC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_B1575466544B9EA3E21A2D4318890444" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_65361BE57155CB056FCC2D43188928DC" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_B1575466544B9EA3E21A2D4318890444" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3393F16BE7DA33ED9B8A2D43188A74C2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_B1575466544B9EA3E21A2D4318890444" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3393F16BE7DA33ED9B8A2D43188A74C2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3393F16BE7DA33ED9B8A2D43188A74C2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_B1575466544B9EA3E21A2D4318890444" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3393F16BE7DA33ED9B8A2D43188A74C2" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_A2016BusinessAcquisitionsMember" xlink:label="loc_clh_A2016BusinessAcquisitionsMember_61E69FC3AE43FB77F58C2D43188AC5C5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3393F16BE7DA33ED9B8A2D43188A74C2" xlink:to="loc_clh_A2016BusinessAcquisitionsMember_61E69FC3AE43FB77F58C2D43188AC5C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NumberOfBusinessesAcquired" xlink:label="loc_us-gaap_NumberOfBusinessesAcquired_18AB6D437BC881ADB7842D43188B640A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D5A8D39C0633F5B7813D2D43188A43F2" xlink:to="loc_us-gaap_NumberOfBusinessesAcquired_18AB6D437BC881ADB7842D43188B640A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_254BBD8E17D1E5FF9F682D43188B59B9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D5A8D39C0633F5B7813D2D43188A43F2" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_254BBD8E17D1E5FF9F682D43188B59B9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_A8A5EDB51131EA8BD5082D43188B951C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D5A8D39C0633F5B7813D2D43188A43F2" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_A8A5EDB51131EA8BD5082D43188B951C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_9E42FD8AF2F0AA8558362D43188B8F6D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D5A8D39C0633F5B7813D2D43188A43F2" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_9E42FD8AF2F0AA8558362D43188B8F6D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BusinessCombinations2017AcquisitionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_4907B0EBA011511FC267682AD39C2921" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_D11D915119E01D7C98BF682AD39A003B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4907B0EBA011511FC267682AD39C2921" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_D11D915119E01D7C98BF682AD39A003B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_6ABDCC8DF63EDE3E723E682AD39A6D8F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_D11D915119E01D7C98BF682AD39A003B" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_6ABDCC8DF63EDE3E723E682AD39A6D8F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D44AACCEB224F8F73146682AD39BBD14_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_6ABDCC8DF63EDE3E723E682AD39A6D8F" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D44AACCEB224F8F73146682AD39BBD14_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D44AACCEB224F8F73146682AD39BBD14" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_6ABDCC8DF63EDE3E723E682AD39A6D8F" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D44AACCEB224F8F73146682AD39BBD14" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LonestarMember" xlink:label="loc_clh_LonestarMember_6E9E59FA7281C098F75C682AD39C459F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D44AACCEB224F8F73146682AD39BBD14" xlink:to="loc_clh_LonestarMember_6E9E59FA7281C098F75C682AD39C459F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_A2017AcquisitionsMember" xlink:label="loc_clh_A2017AcquisitionsMember_34CE81B29F45996D784C682AD39CADEF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D44AACCEB224F8F73146682AD39BBD14" xlink:to="loc_clh_A2017AcquisitionsMember_34CE81B29F45996D784C682AD39CADEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_D3CA818EAA75D7D04331682AD39CBF06" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4907B0EBA011511FC267682AD39C2921" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_D3CA818EAA75D7D04331682AD39CBF06" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_20D766A7102DE187EB83682AD39C9B60" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4907B0EBA011511FC267682AD39C2921" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_20D766A7102DE187EB83682AD39C9B60" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_AAB8FF9808C12190F5D7682AD39C24C7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4907B0EBA011511FC267682AD39C2921" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_AAB8FF9808C12190F5D7682AD39C24C7" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PaymentstoAcquireBusinessCompensationperShare" xlink:label="loc_clh_PaymentstoAcquireBusinessCompensationperShare_D505CA7BCD605B8A43C6682AD39D3BA2" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4907B0EBA011511FC267682AD39C2921" xlink:to="loc_clh_PaymentstoAcquireBusinessCompensationperShare_D505CA7BCD605B8A43C6682AD39D3BA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt_C8569D5BEDCA846E56E4682AD39D64C2" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4907B0EBA011511FC267682AD39C2921" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt_C8569D5BEDCA846E56E4682AD39D64C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_32D2489396765F2F1F13682AD39D44E6" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4907B0EBA011511FC267682AD39C2921" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_32D2489396765F2F1F13682AD39D44E6" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BusinessCombinations2018AcquisitionDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2401A217749025D1F282025096F72705" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2401A217749025D1F282025096F72705" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_7F4BC411EF70229064E7025096F76702" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2401A217749025D1F282025096F72705" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_7F4BC411EF70229064E7025096F76702" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_A691D07DD085E818E364025096F76EF5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7F4BC411EF70229064E7025096F76702" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_A691D07DD085E818E364025096F76EF5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_A691D07DD085E818E364025096F76EF5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7F4BC411EF70229064E7025096F76702" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_A691D07DD085E818E364025096F76EF5" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_VeoliaDivisionMember" xlink:label="loc_clh_VeoliaDivisionMember_09D708FB28769A4E9F86025096F7FCFB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_A691D07DD085E818E364025096F76EF5" xlink:to="loc_clh_VeoliaDivisionMember_09D708FB28769A4E9F86025096F7FCFB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_322F34F100470FF86423025096F72C1D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_322F34F100470FF86423025096F72C1D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_3BE71F36AAD627260C16025096F7A4A1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_3BE71F36AAD627260C16025096F7A4A1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_C4F78EE34F9A3065B698025096F70065" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_C4F78EE34F9A3065B698025096F70065" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_7B36AF39395DAE533EC5025096F72BA4" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_7B36AF39395DAE533EC5025096F72BA4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_5903E1ECF38741F2E79F025096FD2B88" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_5903E1ECF38741F2E79F025096FD2B88" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_82B5BF1262EF2C71AA38025096FD085A" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_82B5BF1262EF2C71AA38025096FD085A" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesClosureandPostClosureLiabilities" xlink:label="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesClosureandPostClosureLiabilities_D5526EF5C4A9648ADDF9025096FD9980" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesClosureandPostClosureLiabilities_D5526EF5C4A9648ADDF9025096FD9980" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_CD6A5DE8FAAEA7A9E993025096FD4F23" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_CD6A5DE8FAAEA7A9E993025096FD4F23" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_DF19DFE177FFFA072655025096FD1D16" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_Goodwill_DF19DFE177FFFA072655025096FD1D16" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_60262ACA6AA2E7919C1F025096FD5A41" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_8BEB007D54EF29D8D42F025096F707DF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_60262ACA6AA2E7919C1F025096FD5A41" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BusinessCombinations2018AcquisitionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2FE7E0B1525DA3B31B1317715AF3EA12" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2FE7E0B1525DA3B31B1317715AF3EA12" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_A2FA65A60EB68E8B8F0F17715AF3B42F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2FE7E0B1525DA3B31B1317715AF3EA12" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_A2FA65A60EB68E8B8F0F17715AF3B42F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D6F98F00A8C3819D793917715AF32681_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_A2FA65A60EB68E8B8F0F17715AF3B42F" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D6F98F00A8C3819D793917715AF32681_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D6F98F00A8C3819D793917715AF32681" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_A2FA65A60EB68E8B8F0F17715AF3B42F" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D6F98F00A8C3819D793917715AF32681" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AcquiredCompanyIncludedinSafetyKleenandEnvironmentalServicesSegmentsMember" xlink:label="loc_clh_AcquiredCompanyIncludedinSafetyKleenandEnvironmentalServicesSegmentsMember_C2EE3EF9A7D4980E7BD117715AF37E3E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D6F98F00A8C3819D793917715AF32681" xlink:to="loc_clh_AcquiredCompanyIncludedinSafetyKleenandEnvironmentalServicesSegmentsMember_C2EE3EF9A7D4980E7BD117715AF37E3E" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_VeoliaDivisionMember" xlink:label="loc_clh_VeoliaDivisionMember_A6E6BA9CE42BDD9C1D2317715AF3B1F0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D6F98F00A8C3819D793917715AF32681" xlink:to="loc_clh_VeoliaDivisionMember_A6E6BA9CE42BDD9C1D2317715AF3B1F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_3D56C5A2A5FCB8B19ABD17715AF3319B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_3D56C5A2A5FCB8B19ABD17715AF3319B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_2B238BB66634D21436E917715AF380E5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_2B238BB66634D21436E917715AF380E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_A8DA470584B3C8A013EB17715AF5D478" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_A8DA470584B3C8A013EB17715AF5D478" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_BusinessCombinationProFormaInformationIncomeLossfromContinuingOperationsbeforeIncomeTaxesofAcquireesinceAcquisitionDateActual" xlink:label="loc_clh_BusinessCombinationProFormaInformationIncomeLossfromContinuingOperationsbeforeIncomeTaxesofAcquireesinceAcquisitionDateActual_BFB227168791AE65D2E217715AF5CED8" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:to="loc_clh_BusinessCombinationProFormaInformationIncomeLossfromContinuingOperationsbeforeIncomeTaxesofAcquireesinceAcquisitionDateActual_BFB227168791AE65D2E217715AF5CED8" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_BusinessCombinationProFormaInformationDepreciationExpense" xlink:label="loc_clh_BusinessCombinationProFormaInformationDepreciationExpense_CDFAFA47495D44D73FBC17715AF51268" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:to="loc_clh_BusinessCombinationProFormaInformationDepreciationExpense_CDFAFA47495D44D73FBC17715AF51268" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_BusinessCombinationProFormaInformationAmortizationofIntangibleAssets" xlink:label="loc_clh_BusinessCombinationProFormaInformationAmortizationofIntangibleAssets_E2D15C4A16462EAC107517715AF5337E" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:to="loc_clh_BusinessCombinationProFormaInformationAmortizationofIntangibleAssets_E2D15C4A16462EAC107517715AF5337E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed" xlink:label="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed_E29CFD7D1E0DC2436C6017715AF57473" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:to="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed_E29CFD7D1E0DC2436C6017715AF57473" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_F1C288A91F39FF4CD66017715AF59677" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_EF576924E5737D90A53317715AF3AF64" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_F1C288A91F39FF4CD66017715AF59677" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BusinessCombinationsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilities" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilitiesAnticipatedPaymentsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilitiesChangesInPostClosureLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:href="clh-20181231.xsd#clh_ClosureAndPostClosureLiabilitiesLineItems" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesLineItems_4C8F06FE047BF321C690278333D42D6C" xlink:type="locator" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ClosureAndPostClosureLiabilitiesTable" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesTable_30515BC6674AB2931F49278333CED472" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesLineItems_4C8F06FE047BF321C690278333D42D6C" xlink:to="loc_clh_ClosureAndPostClosureLiabilitiesTable_30515BC6674AB2931F49278333CED472" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ClosureAndPostClosureLiabilitiesAxis" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesAxis_78FF79B02466A787EF4B278333CE5B25" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesTable_30515BC6674AB2931F49278333CED472" xlink:to="loc_clh_ClosureAndPostClosureLiabilitiesAxis_78FF79B02466A787EF4B278333CE5B25" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ClosureAndPostClosureLiabilitiesDomain" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesDomain_70A9B167F2697B444974278333CEAFCF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesAxis_78FF79B02466A787EF4B278333CE5B25" xlink:to="loc_clh_ClosureAndPostClosureLiabilitiesDomain_70A9B167F2697B444974278333CEAFCF_default" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ClosureAndPostClosureLiabilitiesDomain" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesDomain_70A9B167F2697B444974278333CEAFCF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesAxis_78FF79B02466A787EF4B278333CE5B25" xlink:to="loc_clh_ClosureAndPostClosureLiabilitiesDomain_70A9B167F2697B444974278333CEAFCF" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LandfillRetirementLiabilityMember" xlink:label="loc_clh_LandfillRetirementLiabilityMember_42033FA8A401919E5F59278333D47CEC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesDomain_70A9B167F2697B444974278333CEAFCF" xlink:to="loc_clh_LandfillRetirementLiabilityMember_42033FA8A401919E5F59278333D47CEC" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NonLandfillRetirementLiabilityMember" xlink:label="loc_clh_NonLandfillRetirementLiabilityMember_202E11C4B9E3AD2DC4A2278333D449BD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesDomain_70A9B167F2697B444974278333CEAFCF" xlink:to="loc_clh_NonLandfillRetirementLiabilityMember_202E11C4B9E3AD2DC4A2278333D449BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward" xlink:label="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesLineItems_4C8F06FE047BF321C690278333D42D6C" xlink:to="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetRetirementObligation" xlink:label="loc_us-gaap_AssetRetirementObligation_2B48645CE6EE987487FE278333D5D54C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_us-gaap_AssetRetirementObligation_2B48645CE6EE987487FE278333D5D54C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AssetRetirementObligationLiabilitiesAssumedinAcquisition" xlink:label="loc_clh_AssetRetirementObligationLiabilitiesAssumedinAcquisition_19C43397FE67170E9BD2278333D5C4A9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_clh_AssetRetirementObligationLiabilitiesAssumedinAcquisition_19C43397FE67170E9BD2278333D5C4A9" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AssetRetirementObligationLiabilitiesAssumedfromBusinessAcquisitionsMeasurementPeriodAdjustment" xlink:label="loc_clh_AssetRetirementObligationLiabilitiesAssumedfromBusinessAcquisitionsMeasurementPeriodAdjustment_9FA09CD1CF443AB82CB2278333D5B806" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_clh_AssetRetirementObligationLiabilitiesAssumedfromBusinessAcquisitionsMeasurementPeriodAdjustment_9FA09CD1CF443AB82CB2278333D5B806" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:label="loc_us-gaap_AssetRetirementObligationLiabilitiesIncurred_5B6B35569DAA27C4D36F278333D5F916" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_us-gaap_AssetRetirementObligationLiabilitiesIncurred_5B6B35569DAA27C4D36F278333D5F916" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetRetirementObligationAccretionExpense" xlink:label="loc_us-gaap_AssetRetirementObligationAccretionExpense_893A02F1800D5389A14E278333D5F5FD" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_us-gaap_AssetRetirementObligationAccretionExpense_893A02F1800D5389A14E278333D5F5FD" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AssetRetirementObligationAdjustmentRelatedtoDispositionofBusiness" xlink:label="loc_clh_AssetRetirementObligationAdjustmentRelatedtoDispositionofBusiness_1005710C8846DB16379A278333D6D286" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_clh_AssetRetirementObligationAdjustmentRelatedtoDispositionofBusiness_1005710C8846DB16379A278333D6D286" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AssetRetirementObligationChangesRecordedInStatementOfIncome" xlink:label="loc_clh_AssetRetirementObligationChangesRecordedInStatementOfIncome_90940F621476987509D0278333D64A3E" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_clh_AssetRetirementObligationChangesRecordedInStatementOfIncome_90940F621476987509D0278333D64A3E" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AssetRetirementObligationChangesRecordedinBalanceSheet" xlink:label="loc_clh_AssetRetirementObligationChangesRecordedinBalanceSheet_609BB6BD8FF94408468E278333D6B3D1" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_clh_AssetRetirementObligationChangesRecordedinBalanceSheet_609BB6BD8FF94408468E278333D6B3D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetRetirementObligationLiabilitiesSettled" xlink:label="loc_us-gaap_AssetRetirementObligationLiabilitiesSettled_A0DE87D742F62DC048FF278333D63C3C" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_us-gaap_AssetRetirementObligationLiabilitiesSettled_A0DE87D742F62DC048FF278333D63C3C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetRetirementObligationForeignCurrencyTranslationGainLoss" xlink:label="loc_us-gaap_AssetRetirementObligationForeignCurrencyTranslationGainLoss_2F3200AA646126E2AB84278333D6AFED" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_EF397E7527B7650EC7CE278333D422F6" xlink:to="loc_us-gaap_AssetRetirementObligationForeignCurrencyTranslationGainLoss_2F3200AA646126E2AB84278333D6AFED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CostsIncurredAssetRetirementObligationIncurred" xlink:label="loc_us-gaap_CostsIncurredAssetRetirementObligationIncurred_7849B86B1A6BE1FDA7B2278333D7E473" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesLineItems_4C8F06FE047BF321C690278333D42D6C" xlink:to="loc_us-gaap_CostsIncurredAssetRetirementObligationIncurred_7849B86B1A6BE1FDA7B2278333D7E473" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AssetRetirementObligationsDiscountRate" xlink:label="loc_clh_AssetRetirementObligationsDiscountRate_975F4D3DBA14347D6557278333D72EC8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesLineItems_4C8F06FE047BF321C690278333D42D6C" xlink:to="loc_clh_AssetRetirementObligationsDiscountRate_975F4D3DBA14347D6557278333D72EC8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilitiesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/CommitmentsAndContingenciesFederalStateAndProvincialEnforcementActionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_154CB1CCCDA5EDCBBE80682AD1867940" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_6280248C87A26092BA6D682AD184B5A5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_154CB1CCCDA5EDCBBE80682AD1867940" xlink:to="loc_us-gaap_LossContingenciesTable_6280248C87A26092BA6D682AD184B5A5" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingenciesByNatureOfContingencyAxis" xlink:label="loc_clh_ContingenciesByNatureOfContingencyAxis_2A7D25BB03C4CA6B6B32682AD185869A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_6280248C87A26092BA6D682AD184B5A5" xlink:to="loc_clh_ContingenciesByNatureOfContingencyAxis_2A7D25BB03C4CA6B6B32682AD185869A" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_3CD954D7F047DBA4051A682AD18520A1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_2A7D25BB03C4CA6B6B32682AD185869A" xlink:to="loc_clh_ContingencyNatureDomain_3CD954D7F047DBA4051A682AD18520A1_default" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_3CD954D7F047DBA4051A682AD18520A1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_2A7D25BB03C4CA6B6B32682AD185869A" xlink:to="loc_clh_ContingencyNatureDomain_3CD954D7F047DBA4051A682AD18520A1" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_FederalAndStateEnforcementActionsMember" xlink:label="loc_clh_FederalAndStateEnforcementActionsMember_EB2E2246E146C8BFB6F5682AD185AD52" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingencyNatureDomain_3CD954D7F047DBA4051A682AD18520A1" xlink:to="loc_clh_FederalAndStateEnforcementActionsMember_EB2E2246E146C8BFB6F5682AD185AD52" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_FederalAndStateEnforcementActionsAbstract" xlink:label="loc_clh_FederalAndStateEnforcementActionsAbstract_138721C4BC1022DF800B682AD1867433" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_154CB1CCCDA5EDCBBE80682AD1867940" xlink:to="loc_clh_FederalAndStateEnforcementActionsAbstract_138721C4BC1022DF800B682AD1867433" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingencyPendingClaimsNumber" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_9163D22013A9F7A0FA28682AD186D29A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_FederalAndStateEnforcementActionsAbstract_138721C4BC1022DF800B682AD1867433" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_9163D22013A9F7A0FA28682AD186D29A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:label="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_73FC58406B18F17343D7682AD1862D36" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_FederalAndStateEnforcementActionsAbstract_138721C4BC1022DF800B682AD1867433" xlink:to="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_73FC58406B18F17343D7682AD1862D36" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/CommitmentsAndContingenciesLeasesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/CommitmentsAndContingenciesLegalAndAdministrativeProceedingsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_8F96BE15E7BFBBD5A30E2D4318BCC219" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_CF15C39183CEE08A593D2D4318B995D7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_8F96BE15E7BFBBD5A30E2D4318BCC219" xlink:to="loc_us-gaap_LossContingenciesTable_CF15C39183CEE08A593D2D4318B995D7" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingenciesByNatureOfContingencyAxis" xlink:label="loc_clh_ContingenciesByNatureOfContingencyAxis_5905E2B7BCD79A7DFE642D4318B9DB22" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_CF15C39183CEE08A593D2D4318B995D7" xlink:to="loc_clh_ContingenciesByNatureOfContingencyAxis_5905E2B7BCD79A7DFE642D4318B9DB22" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_37053A62105D715BFDBE2D4318B9DDA5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_5905E2B7BCD79A7DFE642D4318B9DB22" xlink:to="loc_clh_ContingencyNatureDomain_37053A62105D715BFDBE2D4318B9DDA5_default" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_37053A62105D715BFDBE2D4318B9DDA5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_5905E2B7BCD79A7DFE642D4318B9DB22" xlink:to="loc_clh_ContingencyNatureDomain_37053A62105D715BFDBE2D4318B9DDA5" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LegalAndAdministrativeProceedingsMember" xlink:label="loc_clh_LegalAndAdministrativeProceedingsMember_76CF693F09E6B76C18F72D4318BAB608" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingencyNatureDomain_37053A62105D715BFDBE2D4318B9DDA5" xlink:to="loc_clh_LegalAndAdministrativeProceedingsMember_76CF693F09E6B76C18F72D4318BAB608" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_VilleMercierMember" xlink:label="loc_clh_VilleMercierMember_814AB31E052D365CFED72D4318BA2401" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsMember_76CF693F09E6B76C18F72D4318BAB608" xlink:to="loc_clh_VilleMercierMember_814AB31E052D365CFED72D4318BA2401" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_FederalAndStateEnforcementActionsMember" xlink:label="loc_clh_FederalAndStateEnforcementActionsMember_36AF59C0993611CF38392D4318BA921B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingencyNatureDomain_37053A62105D715BFDBE2D4318B9DDA5" xlink:to="loc_clh_FederalAndStateEnforcementActionsMember_36AF59C0993611CF38392D4318BA921B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_2D826B06C80884C1CE702D4318BA7178" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_CF15C39183CEE08A593D2D4318B995D7" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_2D826B06C80884C1CE702D4318BA7178" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_B698B4DB7D45FD1496FE2D4318BB02F5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2D826B06C80884C1CE702D4318BA7178" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_B698B4DB7D45FD1496FE2D4318BB02F5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_B698B4DB7D45FD1496FE2D4318BB02F5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_2D826B06C80884C1CE702D4318BA7178" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_B698B4DB7D45FD1496FE2D4318BB02F5" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_07C7E0A41329ACD073FA2D4318BBB41B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_B698B4DB7D45FD1496FE2D4318BB02F5" xlink:to="loc_clh_SafetyKleenMember_07C7E0A41329ACD073FA2D4318BBB41B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LegalAndAdministrativeProceedingsAbstract" xlink:label="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_8F96BE15E7BFBBD5A30E2D4318BCC219" xlink:to="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingencyAccrualAtCarryingValue" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_95BD737EDF70D201A97B2D4318BCCBDE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_95BD737EDF70D201A97B2D4318BCCBDE" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability" xlink:label="loc_clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability_3451E5BF5D741476F1372D4318BCFA06" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:to="loc_clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability_3451E5BF5D741476F1372D4318BCFA06" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LossContingencyRangeOfLoss" xlink:label="loc_clh_LossContingencyRangeOfLoss_75F6AF535A3C23177CE72D4318BC5FD3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:to="loc_clh_LossContingencyRangeOfLoss_75F6AF535A3C23177CE72D4318BC5FD3" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid" xlink:label="loc_clh_NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid_D8C4A850A06633DF38EA2D4318BD76D3" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:to="loc_clh_NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid_D8C4A850A06633DF38EA2D4318BD76D3" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings" xlink:label="loc_clh_NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings_31BBC2EA748D5D227F882D4318BD0731" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:to="loc_clh_NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings_31BBC2EA748D5D227F882D4318BD0731" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LossContingencyGeneralDamagesSoughtValue" xlink:label="loc_clh_LossContingencyGeneralDamagesSoughtValue_6E3A3F24E856DA21621A2D4318BD3AAB" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:to="loc_clh_LossContingencyGeneralDamagesSoughtValue_6E3A3F24E856DA21621A2D4318BD3AAB" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LossContingencyPunitiveDamagesSoughtValue" xlink:label="loc_clh_LossContingencyPunitiveDamagesSoughtValue_6B6EC338AAD236CC1D2E2D4318BDB8BD" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:to="loc_clh_LossContingencyPunitiveDamagesSoughtValue_6B6EC338AAD236CC1D2E2D4318BDB8BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingencyPendingClaimsNumber" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_263DE7444726C20A9FE32D4318BD15A5" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_263DE7444726C20A9FE32D4318BD15A5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingencyClaimsSettledAndDismissedNumber" xlink:label="loc_us-gaap_LossContingencyClaimsSettledAndDismissedNumber_1C69B6EB6A43B2E5C83D2D4318BD3242" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsAbstract_55A671EF912CBBA40ED62D4318BCB168" xlink:to="loc_us-gaap_LossContingencyClaimsSettledAndDismissedNumber_1C69B6EB6A43B2E5C83D2D4318BD3242" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/CommitmentsAndContingenciesOtherContingenciesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProductLiabilityContingencyLineItems" xlink:label="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProductLiabilityContingencyTable" xlink:label="loc_us-gaap_ProductLiabilityContingencyTable_9CDB7AD26A34B8B0D79062CA694FB514" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:to="loc_us-gaap_ProductLiabilityContingencyTable_9CDB7AD26A34B8B0D79062CA694FB514" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_1D577C70424855EF449362CA694FA103" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ProductLiabilityContingencyTable_9CDB7AD26A34B8B0D79062CA694FB514" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_1D577C70424855EF449362CA694FA103" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3D263743D339403D87ED62CA69501A20_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1D577C70424855EF449362CA694FA103" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3D263743D339403D87ED62CA69501A20_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3D263743D339403D87ED62CA69501A20" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1D577C70424855EF449362CA694FA103" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3D263743D339403D87ED62CA69501A20" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_4FC3F0AD398B464AE84062CA69509A11" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3D263743D339403D87ED62CA69501A20" xlink:to="loc_clh_SafetyKleenMember_4FC3F0AD398B464AE84062CA69509A11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_2C998D18871B8EBE74FF62CA69501A22" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ProductLiabilityContingencyTable_9CDB7AD26A34B8B0D79062CA694FB514" xlink:to="loc_srt_RangeAxis_2C998D18871B8EBE74FF62CA69501A22" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_4ADB5538582926BB78AB62CA6950CFF2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_2C998D18871B8EBE74FF62CA69501A22" xlink:to="loc_srt_RangeMember_4ADB5538582926BB78AB62CA6950CFF2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_4ADB5538582926BB78AB62CA6950CFF2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_2C998D18871B8EBE74FF62CA69501A22" xlink:to="loc_srt_RangeMember_4ADB5538582926BB78AB62CA6950CFF2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_BDC9073291D6DC01758962CA6950E47D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_4ADB5538582926BB78AB62CA6950CFF2" xlink:to="loc_srt_MinimumMember_BDC9073291D6DC01758962CA6950E47D" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DeductibleHealthInsurancePolicy" xlink:label="loc_clh_DeductibleHealthInsurancePolicy_052DF67A3DE9A669C81062CA69508962" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:to="loc_clh_DeductibleHealthInsurancePolicy_052DF67A3DE9A669C81062CA69508962" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DeductiblePerOccurrenceForWorkersCompensation" xlink:label="loc_clh_DeductiblePerOccurrenceForWorkersCompensation_7CCEFC174527CC31932962CA6950AFFF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:to="loc_clh_DeductiblePerOccurrenceForWorkersCompensation_7CCEFC174527CC31932962CA6950AFFF" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DeductiblePerOccurrenceForGeneralLiability" xlink:label="loc_clh_DeductiblePerOccurrenceForGeneralLiability_B8F7EDEF253E0C5C105762CA69513439" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:to="loc_clh_DeductiblePerOccurrenceForGeneralLiability_B8F7EDEF253E0C5C105762CA69513439" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DeductiblePerOccurrenceForVehicleLiability" xlink:label="loc_clh_DeductiblePerOccurrenceForVehicleLiability_5885523012A2ED0335E862CA69513375" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:to="loc_clh_DeductiblePerOccurrenceForVehicleLiability_5885523012A2ED0335E862CA69513375" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RetentionforEnvironmentalImpairment" xlink:label="loc_clh_RetentionforEnvironmentalImpairment_470D38385BE2352FAA1D62CA695156A6" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:to="loc_clh_RetentionforEnvironmentalImpairment_470D38385BE2352FAA1D62CA695156A6" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SelfInsuranceLiabilities" xlink:label="loc_clh_SelfInsuranceLiabilities_1320F8B0A657FEBA144062CA6951EC77" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:to="loc_clh_SelfInsuranceLiabilities_1320F8B0A657FEBA144062CA6951EC77" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FinancialGuaranteeInsuranceContractsClaimLiabilityWeightedAverageRiskFreeDiscountRate" xlink:label="loc_us-gaap_FinancialGuaranteeInsuranceContractsClaimLiabilityWeightedAverageRiskFreeDiscountRate_3AB20E59F7F9E00C7AAF62CA695179BB" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:to="loc_us-gaap_FinancialGuaranteeInsuranceContractsClaimLiabilityWeightedAverageRiskFreeDiscountRate_3AB20E59F7F9E00C7AAF62CA695179BB" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SelfInsuranceLossesExpectedAbstract" xlink:label="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductLiabilityContingencyLineItems_665B9F70A743875BBAFF62CA6950FA13" xlink:to="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AnticipatedSelfInsurancePaymentsYearOne" xlink:label="loc_clh_AnticipatedSelfInsurancePaymentsYearOne_E3AF7477C651BCE1D30462CA6951509E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:to="loc_clh_AnticipatedSelfInsurancePaymentsYearOne_E3AF7477C651BCE1D30462CA6951509E" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AnticipatedSelfInsurancePaymentsYearTwo" xlink:label="loc_clh_AnticipatedSelfInsurancePaymentsYearTwo_7CDB536986D0CBD9ED7B62CA6952A062" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:to="loc_clh_AnticipatedSelfInsurancePaymentsYearTwo_7CDB536986D0CBD9ED7B62CA6952A062" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AnticipatedSelfInsurancePaymentsYearThree" xlink:label="loc_clh_AnticipatedSelfInsurancePaymentsYearThree_093D1E98CA89725159C562CA6952C9D4" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:to="loc_clh_AnticipatedSelfInsurancePaymentsYearThree_093D1E98CA89725159C562CA6952C9D4" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AnticipatedSelfInsurancePaymentsYearFour" xlink:label="loc_clh_AnticipatedSelfInsurancePaymentsYearFour_CE2F017AE9C6D57FB44062CA69524EB6" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:to="loc_clh_AnticipatedSelfInsurancePaymentsYearFour_CE2F017AE9C6D57FB44062CA69524EB6" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AnticipatedSelfInsurancePaymentsYearFive" xlink:label="loc_clh_AnticipatedSelfInsurancePaymentsYearFive_E67B1C9DD268B069C1AE62CA69522E25" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:to="loc_clh_AnticipatedSelfInsurancePaymentsYearFive_E67B1C9DD268B069C1AE62CA69522E25" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AnticipatedSelfInsurancePaymentsThereafter" xlink:label="loc_clh_AnticipatedSelfInsurancePaymentsThereafter_D4AB1F5B47CD06F3407562CA6952E7D1" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:to="loc_clh_AnticipatedSelfInsurancePaymentsThereafter_D4AB1F5B47CD06F3407562CA6952E7D1" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_UndiscountedSelfInsuranceLiabilities" xlink:label="loc_clh_UndiscountedSelfInsuranceLiabilities_26EA483802F0941EDABB62CA69530168" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:to="loc_clh_UndiscountedSelfInsuranceLiabilities_26EA483802F0941EDABB62CA69530168" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SelfInsuranceDiscountRate" xlink:label="loc_clh_SelfInsuranceDiscountRate_71822EB423D5E2B6A3BD62CA695339DE" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:to="loc_clh_SelfInsuranceDiscountRate_71822EB423D5E2B6A3BD62CA695339DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SelfInsuranceReserve" xlink:label="loc_us-gaap_SelfInsuranceReserve_F12031E3A64B80898F9462CA69531ED3" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SelfInsuranceLossesExpectedAbstract_1C36D07B644C318BB44162CA6951753C" xlink:to="loc_us-gaap_SelfInsuranceReserve_F12031E3A64B80898F9462CA69531ED3" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/CommitmentsAndContingenciesSuperfundProceedingsDetails" xlink:type="extended">
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingenciesLineItems" xlink:label="loc_clh_ContingenciesLineItems_74FB50663DEA961F8F642D43189ED76E" xlink:type="locator" />
    <link:loc xlink:href="clh-20181231.xsd#clh_EnvironmentalContingenciesTable" xlink:label="loc_clh_EnvironmentalContingenciesTable_B3435790C4E8C99458662D43189DF926" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_clh_ContingenciesLineItems_74FB50663DEA961F8F642D43189ED76E" xlink:to="loc_clh_EnvironmentalContingenciesTable_B3435790C4E8C99458662D43189DF926" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingenciesByNatureOfContingencyAxis" xlink:label="loc_clh_ContingenciesByNatureOfContingencyAxis_8BC19EC89419AF70C4FB2D43189D2AC7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_clh_EnvironmentalContingenciesTable_B3435790C4E8C99458662D43189DF926" xlink:to="loc_clh_ContingenciesByNatureOfContingencyAxis_8BC19EC89419AF70C4FB2D43189D2AC7" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_AB3BCA73656745FE3E7C2D43189D13A0_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_8BC19EC89419AF70C4FB2D43189D2AC7" xlink:to="loc_clh_ContingencyNatureDomain_AB3BCA73656745FE3E7C2D43189D13A0_default" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_AB3BCA73656745FE3E7C2D43189D13A0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_8BC19EC89419AF70C4FB2D43189D2AC7" xlink:to="loc_clh_ContingencyNatureDomain_AB3BCA73656745FE3E7C2D43189D13A0" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SuperfundProceedingsMember" xlink:label="loc_clh_SuperfundProceedingsMember_F5CF1CD34B4D6590EC632D43189DB837" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingencyNatureDomain_AB3BCA73656745FE3E7C2D43189D13A0" xlink:to="loc_clh_SuperfundProceedingsMember_F5CF1CD34B4D6590EC632D43189DB837" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CertainOtherThirdPartySitesMember" xlink:label="loc_clh_CertainOtherThirdPartySitesMember_D661305096D1FBB3D5322D43189E8D91" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsMember_F5CF1CD34B4D6590EC632D43189DB837" xlink:to="loc_clh_CertainOtherThirdPartySitesMember_D661305096D1FBB3D5322D43189E8D91" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_13B1ADD26C8E9BC6767E2D43189EB36C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingencyNatureDomain_AB3BCA73656745FE3E7C2D43189D13A0" xlink:to="loc_clh_SafetyKleenMember_13B1ADD26C8E9BC6767E2D43189EB36C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SuperfundProceedingsAbstract" xlink:label="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_74FB50663DEA961F8F642D43189ED76E" xlink:to="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SiteContingencyNumberOfSites" xlink:label="loc_clh_SiteContingencyNumberOfSites_6CCB3946256B893ED4092D43189F33C1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_SiteContingencyNumberOfSites_6CCB3946256B893ED4092D43189F33C1" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SiteContingencyNumberOfSitesOwnedByEntity" xlink:label="loc_clh_SiteContingencyNumberOfSitesOwnedByEntity_F59F7205D56788ED13752D43189F1FE8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_SiteContingencyNumberOfSitesOwnedByEntity_F59F7205D56788ED13752D43189F1FE8" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SiteContingencyNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyNumberOfSitesOwnedByThirdParty_D155E6FA3A89E4BD07372D43189F5452" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_SiteContingencyNumberOfSitesOwnedByThirdParty_D155E6FA3A89E4BD07372D43189F5452" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty_7E49CD102301F53FB1F12D43189F145F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty_7E49CD102301F53FB1F12D43189F145F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty_0D55FD979170E54EED7D2D43189F05B0" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty_0D55FD979170E54EED7D2D43189F05B0" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty_D7F7E9AA50DDB68574A22D4318A0D9E2" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty_D7F7E9AA50DDB68574A22D4318A0D9E2" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability" xlink:label="loc_clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability_70874C6EC415DC758A2F2D4318A0E555" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability_70874C6EC415DC758A2F2D4318A0E555" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NumberofSitesPotentialLiabilityExceedsSubstantialQuota" xlink:label="loc_clh_NumberofSitesPotentialLiabilityExceedsSubstantialQuota_42BA9C67F18C0732ED4C2D4318A0B4F2" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_NumberofSitesPotentialLiabilityExceedsSubstantialQuota_42BA9C67F18C0732ED4C2D4318A0B4F2" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty_9F4E62CA67D96934A4372D4318A0CFD9" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty_9F4E62CA67D96934A4372D4318A0CFD9" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty_99F2E9929ADC4EA4AE3E2D4318A031F2" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsAbstract_20D19BB812C25FD1A1DE2D43189E6650" xlink:to="loc_clh_SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty_99F2E9929ADC4EA4AE3E2D4318A031F2" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/CommitmentsAndContingenciesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ConsolidatedBalanceSheets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ConsolidatedStatementsOfComprehensiveIncomeParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ConsolidatedStatementsOfOperations" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_120DBC0410E4F56EE05CDFB3F3DA847C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_StatementTable_120DBC0410E4F56EE05CDFB3F3DA847C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_C92762D183BA5DF88843DFB3F3DA788F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_120DBC0410E4F56EE05CDFB3F3DA847C" xlink:to="loc_srt_ProductOrServiceAxis_C92762D183BA5DF88843DFB3F3DA788F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_D2AF8ABA49D647817458DFB3F3DBC19D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_C92762D183BA5DF88843DFB3F3DA788F" xlink:to="loc_srt_ProductsAndServicesDomain_D2AF8ABA49D647817458DFB3F3DBC19D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_D2AF8ABA49D647817458DFB3F3DBC19D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_C92762D183BA5DF88843DFB3F3DA788F" xlink:to="loc_srt_ProductsAndServicesDomain_D2AF8ABA49D647817458DFB3F3DBC19D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ServiceMember" xlink:label="loc_us-gaap_ServiceMember_A6748CF2EFCC639482E4DFB3F3DB597C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_D2AF8ABA49D647817458DFB3F3DBC19D" xlink:to="loc_us-gaap_ServiceMember_A6748CF2EFCC639482E4DFB3F3DB597C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProductMember" xlink:label="loc_us-gaap_ProductMember_F9452EF78AE712BD5042DFB3F3DC106D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_D2AF8ABA49D647817458DFB3F3DBC19D" xlink:to="loc_us-gaap_ProductMember_F9452EF78AE712BD5042DFB3F3DC106D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="loc_us-gaap_RevenuesAbstract_89DA2C523A1402B215AEDFB3F3DC1A87" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_RevenuesAbstract_89DA2C523A1402B215AEDFB3F3DC1A87" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_2443D3A1B20053726412DFB3F3DC05AB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_89DA2C523A1402B215AEDFB3F3DC1A87" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_2443D3A1B20053726412DFB3F3DC05AB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CostOfRevenueAbstract" xlink:label="loc_us-gaap_CostOfRevenueAbstract_4BD0E6422E330A519DFEDFB3F3DCCEC6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_CostOfRevenueAbstract_4BD0E6422E330A519DFEDFB3F3DCCEC6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_296D84152FAFF2BF9D5DDFB3F3DD1D93" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_4BD0E6422E330A519DFEDFB3F3DCCEC6" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_296D84152FAFF2BF9D5DDFB3F3DD1D93" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_7C084F3403FB3D7BF925DFB3F3DD6BFB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_7C084F3403FB3D7BF925DFB3F3DD6BFB" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AccretionOfEnvironmentalLiabilities" xlink:label="loc_clh_AccretionOfEnvironmentalLiabilities_1B5AA39A17EE6B4A828CDFB3F3DD3ECC" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_clh_AccretionOfEnvironmentalLiabilities_1B5AA39A17EE6B4A828CDFB3F3DD3ECC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_B94EC85446337AEB56EADFB3F3DD7B44" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_B94EC85446337AEB56EADFB3F3DD7B44" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_3FF5C1154AF46886F55DDFB3F3DD807E" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_3FF5C1154AF46886F55DDFB3F3DD807E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_0AD81DA2F4417D6209C1DFB3F3DE2032" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_OperatingIncomeLoss_0AD81DA2F4417D6209C1DFB3F3DE2032" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_CB7706AAC87320F5F9CCDFB3F3DE7FCC" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_CB7706AAC87320F5F9CCDFB3F3DE7FCC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_81165733505B2AE8F805DFB3F3DE8BBC" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_81165733505B2AE8F805DFB3F3DE8BBC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_1A1B8778EA3C72EB9BDFDFB3F3DE7BEC" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_1A1B8778EA3C72EB9BDFDFB3F3DE7BEC" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_InterestExpenseNet" xlink:label="loc_clh_InterestExpenseNet_E6E3CF9F3F2A43BE60B7DFB3F3DED16A" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_clh_InterestExpenseNet_E6E3CF9F3F2A43BE60B7DFB3F3DED16A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_0627F0DD7658AF06151DDFB3F3DF94D0" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_0627F0DD7658AF06151DDFB3F3DF94D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_84220CC3B8AA833FC865DFB3F3DFBF01" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_84220CC3B8AA833FC865DFB3F3DFBF01" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_B3493565577EF7E2A671DFB3F3DF902F" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_NetIncomeLoss_B3493565577EF7E2A671DFB3F3DF902F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_FD491E5CA1AE120D0A7BDFB3F3DF1CBC" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_EarningsPerShareAbstract_FD491E5CA1AE120D0A7BDFB3F3DF1CBC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_EBF9E1C081284E631EACDFB3F3DF4656" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_FD491E5CA1AE120D0A7BDFB3F3DF1CBC" xlink:to="loc_us-gaap_EarningsPerShareBasic_EBF9E1C081284E631EACDFB3F3DF4656" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_36A0F501B0E59FEF7948DFB3F3DFAC1F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_FD491E5CA1AE120D0A7BDFB3F3DF1CBC" xlink:to="loc_us-gaap_EarningsPerShareDiluted_36A0F501B0E59FEF7948DFB3F3DFAC1F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_E0618AB622E1AB41531DDFB3F3E01A11" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_E0618AB622E1AB41531DDFB3F3E01A11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1D48D33C546559ECAEE1DFB3F3E0F84E" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_2B51EFA92A8779242DB0DFB3F3DC0C9D" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1D48D33C546559ECAEE1DFB3F3E0F84E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ConsolidatedStatementsOfOperationsParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_A1F2407F1CE68FF0B180221B743EC404" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_9E0F117DE7260BC27A1E221B74364915" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_A1F2407F1CE68FF0B180221B743EC404" xlink:to="loc_us-gaap_StatementTable_9E0F117DE7260BC27A1E221B74364915" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_BEA674E5486133858F4E221B743864C6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_9E0F117DE7260BC27A1E221B74364915" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_BEA674E5486133858F4E221B743864C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_F50C22AF012D18A215F2221B7439074F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_BEA674E5486133858F4E221B743864C6" xlink:to="loc_us-gaap_EquityComponentDomain_F50C22AF012D18A215F2221B7439074F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_F50C22AF012D18A215F2221B7439074F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_BEA674E5486133858F4E221B743864C6" xlink:to="loc_us-gaap_EquityComponentDomain_F50C22AF012D18A215F2221B7439074F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_C02990B6B776171CD717221B7439B2F1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_F50C22AF012D18A215F2221B7439074F" xlink:to="loc_us-gaap_CommonStockMember_C02990B6B776171CD717221B7439B2F1" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SharesHeldUnderEmployeeParticipationPlanMember" xlink:label="loc_clh_SharesHeldUnderEmployeeParticipationPlanMember_8F732D8E89A240EF0266221B743D518D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_F50C22AF012D18A215F2221B7439074F" xlink:to="loc_clh_SharesHeldUnderEmployeeParticipationPlanMember_8F732D8E89A240EF0266221B743D518D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_530197F84F8B7157E9EE221B743DF49F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_F50C22AF012D18A215F2221B7439074F" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_530197F84F8B7157E9EE221B743DF49F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_EE7194AF36A8C9F30615221B743DE28E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_F50C22AF012D18A215F2221B7439074F" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_EE7194AF36A8C9F30615221B743DE28E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_86A2B52A951C2DF06913221B743EE1F2" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_F50C22AF012D18A215F2221B7439074F" xlink:to="loc_us-gaap_RetainedEarningsMember_86A2B52A951C2DF06913221B743EE1F2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A1F2407F1CE68FF0B180221B743EC404" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_2CC6E07FDC2125B89EFB221B743E39DD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockholdersEquity_2CC6E07FDC2125B89EFB221B743E39DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaap_SharesIssued_185670721EE88762E7F0221B743F3159" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_SharesIssued_185670721EE88762E7F0221B743F3159" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_004A4268F59D77BD31AF221B743F62DD" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_NetIncomeLoss_004A4268F59D77BD31AF221B743F62DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_A6003C95EC21274B5284221B743FA5B3" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_A6003C95EC21274B5284221B743FA5B3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_918955EB8B6B6A41E817221B743F95F4" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_918955EB8B6B6A41E817221B743F95F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_EC9C3C38FC9D87CA2434221B743F0A16" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_EC9C3C38FC9D87CA2434221B743F0A16" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_93D22E20071118BB8C85221B7440339D" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_93D22E20071118BB8C85221B7440339D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_00C102534195D02A0A63221B7440E412" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_00C102534195D02A0A63221B7440E412" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_63ECBA79A79E2BFF5CFB221B7440FF21" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_63ECBA79A79E2BFF5CFB221B7440FF21" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_B3D4497AE71F52AE535F221B74407EE8" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_B3D4497AE71F52AE535F221B74407EE8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_305A25A3A098E393D3DB221B744000C1" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_305A25A3A098E393D3DB221B744000C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_B3EDA71B90F4B6112C55221B744019E2" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_B3EDA71B90F4B6112C55221B744019E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_2D11BDCBD40EFDD7D789221B7441D3C0" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_2D11BDCBD40EFDD7D789221B7441D3C0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_26581572DAA7159B8E1F221B74414F6F" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_26581572DAA7159B8E1F221B74414F6F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet" xlink:label="loc_us-gaap_AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet_5C6C1E54A7CC57F1B0EF221B744162C1" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_08D850D0D1C7BC4A6D61221B743E63AD" xlink:to="loc_us-gaap_AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet_5C6C1E54A7CC57F1B0EF221B744162C1" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ConsolidatedStatementsOfStockholdersEquityParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/DispositionOfBusiness" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/DispositionOfBusiness2016DispositionDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_0BFBB131F640865C2F47682AD32736FF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_0BFBB131F640865C2F47682AD32736FF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_4584D4D7E2957461B6A8682AD3271697" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_0BFBB131F640865C2F47682AD32736FF" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_4584D4D7E2957461B6A8682AD3271697" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_86226F17C1EED7A7E47B682AD328F6AD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_4584D4D7E2957461B6A8682AD3271697" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_86226F17C1EED7A7E47B682AD328F6AD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_86226F17C1EED7A7E47B682AD328F6AD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_4584D4D7E2957461B6A8682AD3271697" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_86226F17C1EED7A7E47B682AD328F6AD" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CatalystServicesMember" xlink:label="loc_clh_CatalystServicesMember_989C511B6391F16AE8F7682AD3289382" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_86226F17C1EED7A7E47B682AD328F6AD" xlink:to="loc_clh_CatalystServicesMember_989C511B6391F16AE8F7682AD3289382" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_8367438EF6FF55CE34C3682AD328B524" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_0BFBB131F640865C2F47682AD32736FF" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_8367438EF6FF55CE34C3682AD328B524" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_31A8EE2B2DB91FEF25C3682AD328FF65_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_8367438EF6FF55CE34C3682AD328B524" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_31A8EE2B2DB91FEF25C3682AD328FF65_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_31A8EE2B2DB91FEF25C3682AD328FF65" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_8367438EF6FF55CE34C3682AD328B524" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_31A8EE2B2DB91FEF25C3682AD328FF65" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_57C3E8917F492433E954682AD329DB97" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_31A8EE2B2DB91FEF25C3682AD328FF65" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_57C3E8917F492433E954682AD329DB97" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_FF639417A090A832E7F4682AD329EEAE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:to="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_FF639417A090A832E7F4682AD329EEAE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent_2B76ECF02EA09142791C682AD329A37F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent_2B76ECF02EA09142791C682AD329A37F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets_63D553FA018036C5E178682AD32A65C4" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets_63D553FA018036C5E178682AD32A65C4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_99ABC66B43B355905BA5682AD32A5E17" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:to="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_99ABC66B43B355905BA5682AD32A5E17" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_49C33E52DD7F4D508A86682AD32AB22F" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:to="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_49C33E52DD7F4D508A86682AD32AB22F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities_4F2880501C7CC50C8B6E682AD32A228D" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities_4F2880501C7CC50C8B6E682AD32A228D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_9421FAC970A6EFF0D12E682AD32A62B1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:to="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_9421FAC970A6EFF0D12E682AD32A62B1" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DisposalGroupIncludingDiscontinuedOperationAssetsLiabilitiesNet" xlink:label="loc_clh_DisposalGroupIncludingDiscontinuedOperationAssetsLiabilitiesNet_6DB967EA60F87D183669682AD32A8DB8" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_29ADBAACBCEFEF35C6D6682AD329170F" xlink:to="loc_clh_DisposalGroupIncludingDiscontinuedOperationAssetsLiabilitiesNet_6DB967EA60F87D183669682AD32A8DB8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/DispositionOfBusiness2016DispositionNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8D6F3854E24D43EFEEB711D7CD27C342" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_ED1DF2DFC30492A1CF2311D7CD25FDE1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8D6F3854E24D43EFEEB711D7CD27C342" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_ED1DF2DFC30492A1CF2311D7CD25FDE1" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_324B9BC1029533B5A67511D7CD258EDB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_ED1DF2DFC30492A1CF2311D7CD25FDE1" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_324B9BC1029533B5A67511D7CD258EDB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_1C219668F9B3FB5BE20B11D7CD2590B3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_324B9BC1029533B5A67511D7CD258EDB" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_1C219668F9B3FB5BE20B11D7CD2590B3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_1C219668F9B3FB5BE20B11D7CD2590B3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_324B9BC1029533B5A67511D7CD258EDB" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_1C219668F9B3FB5BE20B11D7CD2590B3" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CatalystServicesMember" xlink:label="loc_clh_CatalystServicesMember_A526D73C8A5517DA685211D7CD2623BF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_1C219668F9B3FB5BE20B11D7CD2590B3" xlink:to="loc_clh_CatalystServicesMember_A526D73C8A5517DA685211D7CD2623BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_3931405740D961A0282611D7CD26EC4C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_ED1DF2DFC30492A1CF2311D7CD25FDE1" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_3931405740D961A0282611D7CD26EC4C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_B677650B674DDEB1C34511D7CD261CCC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_3931405740D961A0282611D7CD26EC4C" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_B677650B674DDEB1C34511D7CD261CCC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_B677650B674DDEB1C34511D7CD261CCC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_3931405740D961A0282611D7CD26EC4C" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_B677650B674DDEB1C34511D7CD261CCC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_8875032E6AA0101BD49B11D7CD261119" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_B677650B674DDEB1C34511D7CD261CCC" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_8875032E6AA0101BD49B11D7CD261119" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_EE32E27700617D6E1B4D11D7CD273597" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8D6F3854E24D43EFEEB711D7CD27C342" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_EE32E27700617D6E1B4D11D7CD273597" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_C40AAAEC1E91408C812111D7CD27FA45" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8D6F3854E24D43EFEEB711D7CD27C342" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_C40AAAEC1E91408C812111D7CD27FA45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_7E72081631580D28A6D011D7CD271F9B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8D6F3854E24D43EFEEB711D7CD27C342" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_7E72081631580D28A6D011D7CD271F9B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DisposalGroupIncludingDiscontinuedOperationTransactionCosts" xlink:label="loc_clh_DisposalGroupIncludingDiscontinuedOperationTransactionCosts_345633491D52001170EB11D7CD2771F5" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_8D6F3854E24D43EFEEB711D7CD27C342" xlink:to="loc_clh_DisposalGroupIncludingDiscontinuedOperationTransactionCosts_345633491D52001170EB11D7CD2771F5" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/DispositionOfBusiness2017DispositionNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_3F9B733C3C50939887DB71E96E635124" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_02AD69C6B814EE25F72371E96E61805C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_3F9B733C3C50939887DB71E96E635124" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_02AD69C6B814EE25F72371E96E61805C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_43FC5F62117E0F170A7871E96E61E94B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_02AD69C6B814EE25F72371E96E61805C" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_43FC5F62117E0F170A7871E96E61E94B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_EB1AFB1B7B228CD17DB171E96E62B248_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_43FC5F62117E0F170A7871E96E61E94B" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_EB1AFB1B7B228CD17DB171E96E62B248_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_EB1AFB1B7B228CD17DB171E96E62B248" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_43FC5F62117E0F170A7871E96E61E94B" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_EB1AFB1B7B228CD17DB171E96E62B248" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TransformerServicesMember" xlink:label="loc_clh_TransformerServicesMember_ACDAFF6C4A06594AA3DB71E96E62744C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_EB1AFB1B7B228CD17DB171E96E62B248" xlink:to="loc_clh_TransformerServicesMember_ACDAFF6C4A06594AA3DB71E96E62744C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_DE56E1739382412320C371E96E629C65" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_02AD69C6B814EE25F72371E96E61805C" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_DE56E1739382412320C371E96E629C65" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_7D231E82FE03EEF53EC871E96E6237E9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_DE56E1739382412320C371E96E629C65" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_7D231E82FE03EEF53EC871E96E6237E9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_7D231E82FE03EEF53EC871E96E6237E9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_DE56E1739382412320C371E96E629C65" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_7D231E82FE03EEF53EC871E96E6237E9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_AFA80D271EF00648AF1F71E96E63B4C6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_7D231E82FE03EEF53EC871E96E6237E9" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_AFA80D271EF00648AF1F71E96E63B4C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_4FFE6B3236A5123B78A571E96E63E9EB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_3F9B733C3C50939887DB71E96E635124" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_4FFE6B3236A5123B78A571E96E63E9EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_B6F675FB1D33853AD63971E96E6384AA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_3F9B733C3C50939887DB71E96E635124" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_B6F675FB1D33853AD63971E96E6384AA" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DisposalGroupIncludingDiscontinuedOperationTransactionCosts" xlink:label="loc_clh_DisposalGroupIncludingDiscontinuedOperationTransactionCosts_CD39BC2EE69C7B49330471E96E642BCD" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_3F9B733C3C50939887DB71E96E635124" xlink:to="loc_clh_DisposalGroupIncludingDiscontinuedOperationTransactionCosts_CD39BC2EE69C7B49330471E96E642BCD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_602EDEF89AF6AF20CAFB7214202C91BE" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_3F9B733C3C50939887DB71E96E635124" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_602EDEF89AF6AF20CAFB7214202C91BE" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/DispositionOfBusiness2017DispositionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD2A2C4732BE06770FDE682AD340A8D2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD2A2C4732BE06770FDE682AD340A8D2" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_7949B2921C2CE7146F1D682AD340CE3A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD2A2C4732BE06770FDE682AD340A8D2" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_7949B2921C2CE7146F1D682AD340CE3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C231571C5576582CFC63682AD3408DAF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_7949B2921C2CE7146F1D682AD340CE3A" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C231571C5576582CFC63682AD3408DAF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C231571C5576582CFC63682AD3408DAF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_7949B2921C2CE7146F1D682AD340CE3A" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C231571C5576582CFC63682AD3408DAF" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TransformerServicesMember" xlink:label="loc_clh_TransformerServicesMember_F723548B9B4AD1209B8F682AD340045E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_C231571C5576582CFC63682AD3408DAF" xlink:to="loc_clh_TransformerServicesMember_F723548B9B4AD1209B8F682AD340045E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_DF35EAC8E0F119A6EB6A682AD341E0E1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_FD2A2C4732BE06770FDE682AD340A8D2" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_DF35EAC8E0F119A6EB6A682AD341E0E1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_FDBB475BADD6E1733272682AD3416DD1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_DF35EAC8E0F119A6EB6A682AD341E0E1" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_FDBB475BADD6E1733272682AD3416DD1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_FDBB475BADD6E1733272682AD3416DD1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_DF35EAC8E0F119A6EB6A682AD341E0E1" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_FDBB475BADD6E1733272682AD3416DD1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_FE9B4437202D4D733D75682AD34167E6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_FDBB475BADD6E1733272682AD3416DD1" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_FE9B4437202D4D733D75682AD34167E6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_4667BF3C7F83D2E6F70C682AD3427440" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:to="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_4667BF3C7F83D2E6F70C682AD3427440" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent_DB8C58A0DC4EC9B34ED1682AD3427963" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent_DB8C58A0DC4EC9B34ED1682AD3427963" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets_B096CEDE0984F2DC32A4682AD342C2E3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets_B096CEDE0984F2DC32A4682AD342C2E3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_72D75A76994B1507FBB0682AD342A2A4" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:to="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_72D75A76994B1507FBB0682AD342A2A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_E2E2D5315AE7DC6B29F5682AD3438958" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:to="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_E2E2D5315AE7DC6B29F5682AD3438958" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities_24BDD5794527004E1387682AD34304B6" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities_24BDD5794527004E1387682AD34304B6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_AD028A46E5EACAD357BD682AD3438126" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:to="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_AD028A46E5EACAD357BD682AD3438126" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DisposalGroupIncludingDiscontinuedOperationAssetsLiabilitiesNet" xlink:label="loc_clh_DisposalGroupIncludingDiscontinuedOperationAssetsLiabilitiesNet_51D5310D46E24A5FC160682AD343355C" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0965F32D169CB20B1120682AD3422ED5" xlink:to="loc_clh_DisposalGroupIncludingDiscontinuedOperationAssetsLiabilitiesNet_51D5310D46E24A5FC160682AD343355C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/DispositionOfBusinessDispositionOfBusinessIncomeLossAttributableToTransformerServicesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0DA30A44B72A1D800525DFB3F279F031" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_967152F9493314B57402DFB3F278E82D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0DA30A44B72A1D800525DFB3F279F031" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_967152F9493314B57402DFB3F278E82D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_A21435AA0453D78FB39CDFB3F278C425" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_967152F9493314B57402DFB3F278E82D" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_A21435AA0453D78FB39CDFB3F278C425" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_236F2EA97FFD87F1A554DFB3F2784D76_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_A21435AA0453D78FB39CDFB3F278C425" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_236F2EA97FFD87F1A554DFB3F2784D76_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_236F2EA97FFD87F1A554DFB3F2784D76" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_A21435AA0453D78FB39CDFB3F278C425" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_236F2EA97FFD87F1A554DFB3F2784D76" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TransformerServicesMember" xlink:label="loc_clh_TransformerServicesMember_11A0C28F8B231D331BDCDFB3F2798440" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_236F2EA97FFD87F1A554DFB3F2784D76" xlink:to="loc_clh_TransformerServicesMember_11A0C28F8B231D331BDCDFB3F2798440" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_8D4DD539D9559A2CBE20DFB3F2797E92" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_967152F9493314B57402DFB3F278E82D" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_8D4DD539D9559A2CBE20DFB3F2797E92" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_181EBC67D6DC6026E862DFB3F279CB7F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_8D4DD539D9559A2CBE20DFB3F2797E92" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_181EBC67D6DC6026E862DFB3F279CB7F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_181EBC67D6DC6026E862DFB3F279CB7F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_8D4DD539D9559A2CBE20DFB3F2797E92" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_181EBC67D6DC6026E862DFB3F279CB7F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_3956475535C9A9805DC6DFB3F2795649" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_181EBC67D6DC6026E862DFB3F279CB7F" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_3956475535C9A9805DC6DFB3F2795649" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromIndividuallySignificantComponentDisposedOfOrHeldForSaleExcludingDiscontinuedOperationsAttributableToParentBeforeIncomeTax" xlink:label="loc_us-gaap_IncomeLossFromIndividuallySignificantComponentDisposedOfOrHeldForSaleExcludingDiscontinuedOperationsAttributableToParentBeforeIncomeTax_3F9D4E1C402292D0249DDFB3F27AA20E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_0DA30A44B72A1D800525DFB3F279F031" xlink:to="loc_us-gaap_IncomeLossFromIndividuallySignificantComponentDisposedOfOrHeldForSaleExcludingDiscontinuedOperationsAttributableToParentBeforeIncomeTax_3F9D4E1C402292D0249DDFB3F27AA20E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/DispositionOfBusinessIncomeLossAttributableToCatalystServicesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_3304B4B0ED78E18F893BDFB3F262D926" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_8635EB3E78D9BAE18CB1DFB3F261D330" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_3304B4B0ED78E18F893BDFB3F262D926" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_8635EB3E78D9BAE18CB1DFB3F261D330" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_3D751A8A428C14EB3862DFB3F261E0A4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_8635EB3E78D9BAE18CB1DFB3F261D330" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_3D751A8A428C14EB3862DFB3F261E0A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_47F3E444526C6CC723A6DFB3F26186DF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_3D751A8A428C14EB3862DFB3F261E0A4" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_47F3E444526C6CC723A6DFB3F26186DF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_47F3E444526C6CC723A6DFB3F26186DF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_3D751A8A428C14EB3862DFB3F261E0A4" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_47F3E444526C6CC723A6DFB3F26186DF" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CatalystServicesMember" xlink:label="loc_clh_CatalystServicesMember_3E743203BABD5C8114E4DFB3F261DA55" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_47F3E444526C6CC723A6DFB3F26186DF" xlink:to="loc_clh_CatalystServicesMember_3E743203BABD5C8114E4DFB3F261DA55" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_C1243BE0AE6314CDFBCCDFB3F2623939" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_8635EB3E78D9BAE18CB1DFB3F261D330" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_C1243BE0AE6314CDFBCCDFB3F2623939" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_F5829835D53686C318BCDFB3F26261A4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_C1243BE0AE6314CDFBCCDFB3F2623939" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_F5829835D53686C318BCDFB3F26261A4_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_F5829835D53686C318BCDFB3F26261A4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_C1243BE0AE6314CDFBCCDFB3F2623939" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_F5829835D53686C318BCDFB3F26261A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_BD3BCC43C4CB2752D0CDDFB3F2622F9A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_F5829835D53686C318BCDFB3F26261A4" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_BD3BCC43C4CB2752D0CDDFB3F2622F9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromIndividuallySignificantComponentDisposedOfOrHeldForSaleExcludingDiscontinuedOperationsAttributableToParentBeforeIncomeTax" xlink:label="loc_us-gaap_IncomeLossFromIndividuallySignificantComponentDisposedOfOrHeldForSaleExcludingDiscontinuedOperationsAttributableToParentBeforeIncomeTax_5D452C427C7456F8D1BCDFB3F263CA7F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_3304B4B0ED78E18F893BDFB3F262D926" xlink:to="loc_us-gaap_IncomeLossFromIndividuallySignificantComponentDisposedOfOrHeldForSaleExcludingDiscontinuedOperationsAttributableToParentBeforeIncomeTax_5D452C427C7456F8D1BCDFB3F263CA7F" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/DispositionOfBusinessTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/DocumentAndEntityInformation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/EarningsLossPerShare" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/EarningsLossPerShareAntiDilutiveSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_7FCF96A1129D9ADF7663BA16357B5E6E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_C687C346C95FAB0D2000BA16357A81DD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_7FCF96A1129D9ADF7663BA16357B5E6E" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_C687C346C95FAB0D2000BA16357A81DD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_06EE338C71420F22CCF6BA16357A5CE6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_C687C346C95FAB0D2000BA16357A81DD" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_06EE338C71420F22CCF6BA16357A5CE6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8D6F7CFD494982C94667BA16357A2BE5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_06EE338C71420F22CCF6BA16357A5CE6" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8D6F7CFD494982C94667BA16357A2BE5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8D6F7CFD494982C94667BA16357A2BE5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_06EE338C71420F22CCF6BA16357A5CE6" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8D6F7CFD494982C94667BA16357A2BE5" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RestrictedStockandPerformanceStockAwardsMember" xlink:label="loc_clh_RestrictedStockandPerformanceStockAwardsMember_C2D9DD628726397DCEECBA16357B9208" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8D6F7CFD494982C94667BA16357A2BE5" xlink:to="loc_clh_RestrictedStockandPerformanceStockAwardsMember_C2D9DD628726397DCEECBA16357B9208" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_4D6D6BB7BEC0E578C86DBA16357B48EC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8D6F7CFD494982C94667BA16357A2BE5" xlink:to="loc_us-gaap_RestrictedStockMember_4D6D6BB7BEC0E578C86DBA16357B48EC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_F591D7BD7BC5F7FF8929BA16357B5BFA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_7FCF96A1129D9ADF7663BA16357B5E6E" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_F591D7BD7BC5F7FF8929BA16357B5BFA" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/EarningsLossPerShareReconciliationOfBasicAndDilutedEarningsPerShareComputationsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/EarningsLossPerShareTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/FinancingArrangements" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/FinancingArrangementsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_C8CEBD9CC50C2E962C5D11D7CBD4660D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_DebtInstrumentTable_C8CEBD9CC50C2E962C5D11D7CBD4660D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_7ABB4B1D0CA76C85FC1911D7CBD4A11C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C8CEBD9CC50C2E962C5D11D7CBD4660D" xlink:to="loc_us-gaap_CreditFacilityAxis_7ABB4B1D0CA76C85FC1911D7CBD4A11C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_7B39DC28A7183C87048711D7CBD4320C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_7ABB4B1D0CA76C85FC1911D7CBD4A11C" xlink:to="loc_us-gaap_CreditFacilityDomain_7B39DC28A7183C87048711D7CBD4320C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_7B39DC28A7183C87048711D7CBD4320C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_7ABB4B1D0CA76C85FC1911D7CBD4A11C" xlink:to="loc_us-gaap_CreditFacilityDomain_7B39DC28A7183C87048711D7CBD4320C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_BF8B24C8671F641FA9A311D7CBD5D055" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_7B39DC28A7183C87048711D7CBD4320C" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_BF8B24C8671F641FA9A311D7CBD5D055" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_5FD5B316D0DF7461DD8E11D7CBD57C4A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C8CEBD9CC50C2E962C5D11D7CBD4660D" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_5FD5B316D0DF7461DD8E11D7CBD57C4A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_65630D4D2E30844AF22D11D7CBD51544_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_5FD5B316D0DF7461DD8E11D7CBD57C4A" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_65630D4D2E30844AF22D11D7CBD51544_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_65630D4D2E30844AF22D11D7CBD51544" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_5FD5B316D0DF7461DD8E11D7CBD57C4A" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_65630D4D2E30844AF22D11D7CBD51544" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_F9257B37F5A8F8606CE911D7CBD53A7F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_65630D4D2E30844AF22D11D7CBD51544" xlink:to="loc_us-gaap_InterestRateSwapMember_F9257B37F5A8F8606CE911D7CBD53A7F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_3AEC81A9F63CF98BAFCB11D7CBD6A110" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C8CEBD9CC50C2E962C5D11D7CBD4660D" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_3AEC81A9F63CF98BAFCB11D7CBD6A110" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_E002923631DBB07EE75111D7CBD6B45B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3AEC81A9F63CF98BAFCB11D7CBD6A110" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_E002923631DBB07EE75111D7CBD6B45B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_E002923631DBB07EE75111D7CBD6B45B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3AEC81A9F63CF98BAFCB11D7CBD6A110" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_E002923631DBB07EE75111D7CBD6B45B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SecuredDebtMember" xlink:label="loc_us-gaap_SecuredDebtMember_BF06CA77BCA1B7EBCCB011D7CBD66901" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_E002923631DBB07EE75111D7CBD6B45B" xlink:to="loc_us-gaap_SecuredDebtMember_BF06CA77BCA1B7EBCCB011D7CBD66901" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_BC0DE7FAE81A598F402911D7CBD64F7C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_E002923631DBB07EE75111D7CBD6B45B" xlink:to="loc_us-gaap_SeniorNotesMember_BC0DE7FAE81A598F402911D7CBD64F7C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditMember" xlink:label="loc_us-gaap_LineOfCreditMember_0A18673840F0EE46243011D7CBD7922B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_E002923631DBB07EE75111D7CBD6B45B" xlink:to="loc_us-gaap_LineOfCreditMember_0A18673840F0EE46243011D7CBD7922B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LetterOfCreditMember" xlink:label="loc_us-gaap_LetterOfCreditMember_47A85EB870782CBE286611D7CBD719ED" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_E002923631DBB07EE75111D7CBD6B45B" xlink:to="loc_us-gaap_LetterOfCreditMember_47A85EB870782CBE286611D7CBD719ED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_7FE93EBDDA1484A1201D11D7CBD725AD" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C8CEBD9CC50C2E962C5D11D7CBD4660D" xlink:to="loc_us-gaap_DebtInstrumentAxis_7FE93EBDDA1484A1201D11D7CBD725AD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_5189FBA75F549761D51211D7CBD72E20_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_7FE93EBDDA1484A1201D11D7CBD725AD" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_5189FBA75F549761D51211D7CBD72E20_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_5189FBA75F549761D51211D7CBD72E20" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_7FE93EBDDA1484A1201D11D7CBD725AD" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_5189FBA75F549761D51211D7CBD72E20" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_FirstAmendmentMember" xlink:label="loc_clh_FirstAmendmentMember_4B79FAC5C4CC47A111B511D7CBD79002" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_5189FBA75F549761D51211D7CBD72E20" xlink:to="loc_clh_FirstAmendmentMember_4B79FAC5C4CC47A111B511D7CBD79002" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TermLoanAgreementMember" xlink:label="loc_clh_TermLoanAgreementMember_A3992F29C4C1AB00662F11D7CBD8FB6B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_5189FBA75F549761D51211D7CBD72E20" xlink:to="loc_clh_TermLoanAgreementMember_A3992F29C4C1AB00662F11D7CBD8FB6B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_UnsecuredSeniorNotes2020Member" xlink:label="loc_clh_UnsecuredSeniorNotes2020Member_4EF6ABC5D5238CDCD5AB11D7CBD89093" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_5189FBA75F549761D51211D7CBD72E20" xlink:to="loc_clh_UnsecuredSeniorNotes2020Member_4EF6ABC5D5238CDCD5AB11D7CBD89093" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_UnsecuredSeniorNotes2021Member" xlink:label="loc_clh_UnsecuredSeniorNotes2021Member_B9814AAB73978787989711D7CBD8B2E6" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_5189FBA75F549761D51211D7CBD72E20" xlink:to="loc_clh_UnsecuredSeniorNotes2021Member_B9814AAB73978787989711D7CBD8B2E6" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TermLoanswithInterestRateSwapAgreementsMember" xlink:label="loc_clh_TermLoanswithInterestRateSwapAgreementsMember_D21F55C35196D82251CD11D7CBD839E9" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_5189FBA75F549761D51211D7CBD72E20" xlink:to="loc_clh_TermLoanswithInterestRateSwapAgreementsMember_D21F55C35196D82251CD11D7CBD839E9" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_6AF1C1B73B81ECFDF58A11D7CBD8636F" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C8CEBD9CC50C2E962C5D11D7CBD4660D" xlink:to="loc_dei_LegalEntityAxis_6AF1C1B73B81ECFDF58A11D7CBD8636F" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_36EEE352D92EDC11B5C611D7CBD8CC2D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_6AF1C1B73B81ECFDF58A11D7CBD8636F" xlink:to="loc_dei_EntityDomain_36EEE352D92EDC11B5C611D7CBD8CC2D_default" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_36EEE352D92EDC11B5C611D7CBD8CC2D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_6AF1C1B73B81ECFDF58A11D7CBD8636F" xlink:to="loc_dei_EntityDomain_36EEE352D92EDC11B5C611D7CBD8CC2D" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ParentandDomesticSubsidiariesMember" xlink:label="loc_clh_ParentandDomesticSubsidiariesMember_22C752822B411870426311D7CBD9325F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_36EEE352D92EDC11B5C611D7CBD8CC2D" xlink:to="loc_clh_ParentandDomesticSubsidiariesMember_22C752822B411870426311D7CBD9325F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CanadianSubsidiariesMember" xlink:label="loc_clh_CanadianSubsidiariesMember_5F43858BA76E51AE832611D7CBD93069" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_36EEE352D92EDC11B5C611D7CBD8CC2D" xlink:to="loc_clh_CanadianSubsidiariesMember_5F43858BA76E51AE832611D7CBD93069" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_F343499A10349626EB1B11D7CBD941EE" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C8CEBD9CC50C2E962C5D11D7CBD4660D" xlink:to="loc_srt_RangeAxis_F343499A10349626EB1B11D7CBD941EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_692E94530A76333627E411D7CBD9DC0A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_F343499A10349626EB1B11D7CBD941EE" xlink:to="loc_srt_RangeMember_692E94530A76333627E411D7CBD9DC0A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_692E94530A76333627E411D7CBD9DC0A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_F343499A10349626EB1B11D7CBD941EE" xlink:to="loc_srt_RangeMember_692E94530A76333627E411D7CBD9DC0A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_D5DB8E99546CA972EEEC11D7CBDAF345" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_692E94530A76333627E411D7CBD9DC0A" xlink:to="loc_srt_MinimumMember_D5DB8E99546CA972EEEC11D7CBDAF345" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_E8E3A0F5FA79100895DD11D7CBDA5754" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_692E94530A76333627E411D7CBD9DC0A" xlink:to="loc_srt_MaximumMember_E8E3A0F5FA79100895DD11D7CBDA5754" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_4C38206163110ABF333111D7CBDA92CB" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C8CEBD9CC50C2E962C5D11D7CBD4660D" xlink:to="loc_us-gaap_VariableRateAxis_4C38206163110ABF333111D7CBDA92CB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_B48EB8030A53CBEDDA0611D7CBDA5AC5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_4C38206163110ABF333111D7CBDA92CB" xlink:to="loc_us-gaap_VariableRateDomain_B48EB8030A53CBEDDA0611D7CBDA5AC5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_B48EB8030A53CBEDDA0611D7CBDA5AC5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_4C38206163110ABF333111D7CBDA92CB" xlink:to="loc_us-gaap_VariableRateDomain_B48EB8030A53CBEDDA0611D7CBDA5AC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EurodollarMember" xlink:label="loc_us-gaap_EurodollarMember_A8032E1E8755FAA5D55A11D7CBDABB81" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B48EB8030A53CBEDDA0611D7CBDA5AC5" xlink:to="loc_us-gaap_EurodollarMember_A8032E1E8755FAA5D55A11D7CBDABB81" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_98EBECB6190E8B52166D11D7CBDB8609" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B48EB8030A53CBEDDA0611D7CBDA5AC5" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_98EBECB6190E8B52166D11D7CBDB8609" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BaseRateMember" xlink:label="loc_us-gaap_BaseRateMember_0E3070F94956C5B4735311D7CBDBE70A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B48EB8030A53CBEDDA0611D7CBDA5AC5" xlink:to="loc_us-gaap_BaseRateMember_0E3070F94956C5B4735311D7CBDBE70A" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DebtInstrumentInterestRateDecreaseinStatedPercentage" xlink:label="loc_clh_DebtInstrumentInterestRateDecreaseinStatedPercentage_B4189C16D8D4FF9F0D9811D7CBDB16FF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_clh_DebtInstrumentInterestRateDecreaseinStatedPercentage_B4189C16D8D4FF9F0D9811D7CBDB16FF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_3C432C38DD7D84065B4E11D7CBDC098F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_3C432C38DD7D84065B4E11D7CBDC098F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LineofCreditFacilityIncreaseinMaximumBorrowingCapacity" xlink:label="loc_clh_LineofCreditFacilityIncreaseinMaximumBorrowingCapacity_5EE3432399710849428411D7CBDCAADD" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_clh_LineofCreditFacilityIncreaseinMaximumBorrowingCapacity_5EE3432399710849428411D7CBDCAADD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromNotesPayable" xlink:label="loc_us-gaap_ProceedsFromNotesPayable_321E4D8D62D1407D890D11D7CBDC5E07" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_ProceedsFromNotesPayable_321E4D8D62D1407D890D11D7CBDC5E07" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LongtermDebtPurchasePrice" xlink:label="loc_clh_LongtermDebtPurchasePrice_AC8E462E55FF5F61DA7F11D7CBDCC6F5" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_clh_LongtermDebtPurchasePrice_AC8E462E55FF5F61DA7F11D7CBDCC6F5" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LongtermDebtPurchasePriceAccruedInterest" xlink:label="loc_clh_LongtermDebtPurchasePriceAccruedInterest_8077822F5CA077F9629611D7CBDC8914" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_clh_LongtermDebtPurchasePriceAccruedInterest_8077822F5CA077F9629611D7CBDC8914" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DebtRedemptionFees" xlink:label="loc_clh_DebtRedemptionFees_A71DB06AC7A84A37647F11FD690D3D2A" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_clh_DebtRedemptionFees_A71DB06AC7A84A37647F11FD690D3D2A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtFairValue" xlink:label="loc_us-gaap_LongTermDebtFairValue_EF190038C899E46551AC11D7CBDDFF1E" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_LongTermDebtFairValue_EF190038C899E46551AC11D7CBDDFF1E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_B5A6C40C0034A72CDF1411D7CBDD4046" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_B5A6C40C0034A72CDF1411D7CBDD4046" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentRepurchaseAmount" xlink:label="loc_us-gaap_DebtInstrumentRepurchaseAmount_3D200EBD7262E9E433FE11D7CBDD052F" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_DebtInstrumentRepurchaseAmount_3D200EBD7262E9E433FE11D7CBDD052F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_79FFB0E4AFF595E899FE11D7CBDD2871" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_79FFB0E4AFF595E899FE11D7CBDD2871" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CreditAvailableSubjecttoPercentageofAccountsReceivable" xlink:label="loc_clh_CreditAvailableSubjecttoPercentageofAccountsReceivable_39358DE8832C68E54E3B11D7CBDD16BF" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_clh_CreditAvailableSubjecttoPercentageofAccountsReceivable_39358DE8832C68E54E3B11D7CBDD16BF" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CreditAvailableSubjecttoPercentageofCashDeposited" xlink:label="loc_clh_CreditAvailableSubjecttoPercentageofCashDeposited_804386EE006DB308081111D7CBDD88A3" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_clh_CreditAvailableSubjecttoPercentageofCashDeposited_804386EE006DB308081111D7CBDD88A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_1685CF681CD35CA5702711D7CBDDB0EE" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_1685CF681CD35CA5702711D7CBDDB0EE" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DebtInstrumentSpreadonVariableRatePeriodforMeasurementofAverageLiquidity" xlink:label="loc_clh_DebtInstrumentSpreadonVariableRatePeriodforMeasurementofAverageLiquidity_4EA5ED4B5595397AC27811D7CBDE2B62" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_clh_DebtInstrumentSpreadonVariableRatePeriodforMeasurementofAverageLiquidity_4EA5ED4B5595397AC27811D7CBDE2B62" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_4145C5B3B3CEEE6C068911D7CBDE0F96" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_4145C5B3B3CEEE6C068911D7CBDE0F96" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_C3005212093D1453734A11D7CBDEE29F" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_C3005212093D1453734A11D7CBDEE29F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="loc_us-gaap_RepaymentsOfLinesOfCredit_ED221F7B947A66501BF511D7CBDE66FB" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_RepaymentsOfLinesOfCredit_ED221F7B947A66501BF511D7CBDE66FB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_38D59DEDBC1BF19AD78411D7CBDEA35D" xlink:type="locator" />
    <link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_38D59DEDBC1BF19AD78411D7CBDEA35D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_B5F31662D83713DD5DFA11D7CBDF29BB" xlink:type="locator" />
    <link:definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_B5F31662D83713DD5DFA11D7CBDF29BB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebt" xlink:label="loc_us-gaap_LongTermDebt_117764C5E2AB59BF4CE511D7CBDFA0D8" xlink:type="locator" />
    <link:definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_LongTermDebt_117764C5E2AB59BF4CE511D7CBDFA0D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_CED63BA96AD664AFC13311D7CBDFFE43" xlink:type="locator" />
    <link:definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_invest_DerivativeNotionalAmount_CED63BA96AD664AFC13311D7CBDFFE43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_2586F6C2922E0C69B45F11D7CBDF8244" xlink:type="locator" />
    <link:definitionArc order="23" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_2586F6C2922E0C69B45F11D7CBDF8244" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_6C0F87BCB2DB8046CC1611D7CBDF81AF" xlink:type="locator" />
    <link:definitionArc order="24" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6FDF0BA938852FED441E11D7CBDBA662" xlink:to="loc_us-gaap_DerivativeLiabilities_6C0F87BCB2DB8046CC1611D7CBDF81AF" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/FinancingArrangementsSummaryOfFinancingArrangementsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_DE5D8716A9825F20AE822A74A1E34AD6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_5E9C127A398A30667B412A74A1DFE7ED" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_DE5D8716A9825F20AE822A74A1E34AD6" xlink:to="loc_us-gaap_DebtInstrumentTable_5E9C127A398A30667B412A74A1DFE7ED" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_C2AD0CA29EC35E85550B2A74A1E09BE1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_5E9C127A398A30667B412A74A1DFE7ED" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_C2AD0CA29EC35E85550B2A74A1E09BE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_160804840437BF5F532C2A74A1E11D86_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_C2AD0CA29EC35E85550B2A74A1E09BE1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_160804840437BF5F532C2A74A1E11D86_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_160804840437BF5F532C2A74A1E11D86" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_C2AD0CA29EC35E85550B2A74A1E09BE1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_160804840437BF5F532C2A74A1E11D86" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SecuredDebtMember" xlink:label="loc_us-gaap_SecuredDebtMember_10BAEAD8B6764198B6372A74A1E11050" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_160804840437BF5F532C2A74A1E11D86" xlink:to="loc_us-gaap_SecuredDebtMember_10BAEAD8B6764198B6372A74A1E11050" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_F9CBD5859737DE911DB02A74A1E157E6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_160804840437BF5F532C2A74A1E11D86" xlink:to="loc_us-gaap_SeniorNotesMember_F9CBD5859737DE911DB02A74A1E157E6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_6E5E887F026EE846AAC42A74A1E2823A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_5E9C127A398A30667B412A74A1DFE7ED" xlink:to="loc_us-gaap_DebtInstrumentAxis_6E5E887F026EE846AAC42A74A1E2823A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_E593C0E6E1A3A4E9078D2A74A1E223CA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_6E5E887F026EE846AAC42A74A1E2823A" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_E593C0E6E1A3A4E9078D2A74A1E223CA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_E593C0E6E1A3A4E9078D2A74A1E223CA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_6E5E887F026EE846AAC42A74A1E2823A" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_E593C0E6E1A3A4E9078D2A74A1E223CA" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TermLoanAgreementMember" xlink:label="loc_clh_TermLoanAgreementMember_755500AEE4453C9F2B782A74A1E27459" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_E593C0E6E1A3A4E9078D2A74A1E223CA" xlink:to="loc_clh_TermLoanAgreementMember_755500AEE4453C9F2B782A74A1E27459" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_UnsecuredSeniorNotes2020Member" xlink:label="loc_clh_UnsecuredSeniorNotes2020Member_0DE6580E829C44477A222A74A1E3232C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_E593C0E6E1A3A4E9078D2A74A1E223CA" xlink:to="loc_clh_UnsecuredSeniorNotes2020Member_0DE6580E829C44477A222A74A1E3232C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_UnsecuredSeniorNotes2021Member" xlink:label="loc_clh_UnsecuredSeniorNotes2021Member_FBDEF8FEE5FBFB8E5F692A74A1E3BF66" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_E593C0E6E1A3A4E9078D2A74A1E223CA" xlink:to="loc_clh_UnsecuredSeniorNotes2021Member_FBDEF8FEE5FBFB8E5F692A74A1E3BF66" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="loc_us-gaap_LongTermDebtCurrent_5CF3AB239EEDE0F20A8B2A74A1E39FD2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_DE5D8716A9825F20AE822A74A1E34AD6" xlink:to="loc_us-gaap_LongTermDebtCurrent_5CF3AB239EEDE0F20A8B2A74A1E39FD2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_5A77E4385DEF93A7D1E42A74A1E4F3F4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_DE5D8716A9825F20AE822A74A1E34AD6" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_5A77E4385DEF93A7D1E42A74A1E4F3F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_06916F07B1A0807AEC372A74A1E43112" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_DE5D8716A9825F20AE822A74A1E34AD6" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_06916F07B1A0807AEC372A74A1E43112" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_EBC5424DFF24747F30802A74A1E47F2C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_DE5D8716A9825F20AE822A74A1E34AD6" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_EBC5424DFF24747F30802A74A1E47F2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_9567AD25682EF2C49FD52A74A1E5C709" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_DE5D8716A9825F20AE822A74A1E34AD6" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_9567AD25682EF2C49FD52A74A1E5C709" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/FinancingArrangementsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsChangesToGoodwillDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillLineItems" xlink:label="loc_us-gaap_GoodwillLineItems_FE5597B9671B58A0D8072A6D1EA7AF7F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_50292EDD6F4C5408ADD32A6D1EA285F6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_FE5597B9671B58A0D8072A6D1EA7AF7F" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_50292EDD6F4C5408ADD32A6D1EA285F6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_44FEA0505D4F9D0B02702A6D1EA37CCC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_50292EDD6F4C5408ADD32A6D1EA285F6" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_44FEA0505D4F9D0B02702A6D1EA37CCC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3BBC2FCF3EE7B421E54B2A6D1EA4C17D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_44FEA0505D4F9D0B02702A6D1EA37CCC" xlink:to="loc_us-gaap_SegmentDomain_3BBC2FCF3EE7B421E54B2A6D1EA4C17D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3BBC2FCF3EE7B421E54B2A6D1EA4C17D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_44FEA0505D4F9D0B02702A6D1EA37CCC" xlink:to="loc_us-gaap_SegmentDomain_3BBC2FCF3EE7B421E54B2A6D1EA4C17D" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_EnvironmentalServicesMember" xlink:label="loc_clh_EnvironmentalServicesMember_7D50DE9A3A6E9119A1472A917B9D52A3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3BBC2FCF3EE7B421E54B2A6D1EA4C17D" xlink:to="loc_clh_EnvironmentalServicesMember_7D50DE9A3A6E9119A1472A917B9D52A3" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_C89FC311EFC9AD8378342A6D1EA5E343" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3BBC2FCF3EE7B421E54B2A6D1EA4C17D" xlink:to="loc_clh_SafetyKleenMember_C89FC311EFC9AD8378342A6D1EA5E343" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillRollForward" xlink:label="loc_us-gaap_GoodwillRollForward_F3A028E831A589DD2B982A6D1EA793D6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_FE5597B9671B58A0D8072A6D1EA7AF7F" xlink:to="loc_us-gaap_GoodwillRollForward_F3A028E831A589DD2B982A6D1EA793D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_2D2B110C2774403E4C0F2A6D1EA833D8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_F3A028E831A589DD2B982A6D1EA793D6" xlink:to="loc_us-gaap_Goodwill_2D2B110C2774403E4C0F2A6D1EA833D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_38A84E735A9B5F73BF5B2A6D1EA8CEC7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_F3A028E831A589DD2B982A6D1EA793D6" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_38A84E735A9B5F73BF5B2A6D1EA8CEC7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_9E8926D69D15A2218F212A6D1EA91B5E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_F3A028E831A589DD2B982A6D1EA793D6" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_9E8926D69D15A2218F212A6D1EA91B5E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit" xlink:label="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_6001A9DDD6330AD504A72A6D1EA96975" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_F3A028E831A589DD2B982A6D1EA793D6" xlink:to="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_6001A9DDD6330AD504A72A6D1EA96975" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_0D6A6E811B42E771FD6E2A6D1EA909C8" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_F3A028E831A589DD2B982A6D1EA793D6" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_0D6A6E811B42E771FD6E2A6D1EA909C8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_BAC8445E2B88A90ECFE72A6D1EA9DD0B" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_F3A028E831A589DD2B982A6D1EA793D6" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_BAC8445E2B88A90ECFE72A6D1EA9DD0B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsExpectedAmortizationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsFiniteLivedAndIndefiniteLivedIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_ECAB2CC1791CA5F69A02BA437E4040ED" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_F45A99EC381333A20066BA437E3E3F96" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_ECAB2CC1791CA5F69A02BA437E4040ED" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_F45A99EC381333A20066BA437E3E3F96" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_85C19949683164F0BE44BA437E3EED63" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_F45A99EC381333A20066BA437E3E3F96" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_85C19949683164F0BE44BA437E3EED63" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_19A35DEFC57465D57CBBBA437E3E6CB0_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_85C19949683164F0BE44BA437E3EED63" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_19A35DEFC57465D57CBBBA437E3E6CB0_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_19A35DEFC57465D57CBBBA437E3E6CB0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_85C19949683164F0BE44BA437E3EED63" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_19A35DEFC57465D57CBBBA437E3E6CB0" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PermitsMember" xlink:label="loc_clh_PermitsMember_2FBACF7114579AEE99F5BA437E3FA973" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_19A35DEFC57465D57CBBBA437E3E6CB0" xlink:to="loc_clh_PermitsMember_2FBACF7114579AEE99F5BA437E3FA973" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_5CB8F20B4E2E9BD7FF7CBA437E3F96F0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_19A35DEFC57465D57CBBBA437E3E6CB0" xlink:to="loc_us-gaap_CustomerRelationshipsMember_5CB8F20B4E2E9BD7FF7CBA437E3F96F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherIntangibleAssetsMember" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_A2CF82E3B553A8074A11BA437E3F9BF3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_19A35DEFC57465D57CBBBA437E3E6CB0" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_A2CF82E3B553A8074A11BA437E3F9BF3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_997C7B9FCC45773167DFBA437E3F902F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_F45A99EC381333A20066BA437E3E3F96" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_997C7B9FCC45773167DFBA437E3F902F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_0901391CD601776133FDBA437E3F6CB5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_997C7B9FCC45773167DFBA437E3F902F" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_0901391CD601776133FDBA437E3F6CB5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_0901391CD601776133FDBA437E3F6CB5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_997C7B9FCC45773167DFBA437E3F902F" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_0901391CD601776133FDBA437E3F6CB5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TrademarksMember" xlink:label="loc_us-gaap_TrademarksMember_BC204E22EF1478E9B730BA437E4095DC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_0901391CD601776133FDBA437E3F6CB5" xlink:to="loc_us-gaap_TrademarksMember_BC204E22EF1478E9B730BA437E4095DC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_9033433E7EC906E9CCA2BA437E40C8E4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_ECAB2CC1791CA5F69A02BA437E4040ED" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_9033433E7EC906E9CCA2BA437E40C8E4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_81C43613010E306F4D7BBA437E416F84" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_ECAB2CC1791CA5F69A02BA437E4040ED" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_81C43613010E306F4D7BBA437E416F84" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_153E5826AAFC2ACD8AC8BA437E417268" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_ECAB2CC1791CA5F69A02BA437E4040ED" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_153E5826AAFC2ACD8AC8BA437E417268" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_284E04E849284192819CBA437E41A2E7" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_ECAB2CC1791CA5F69A02BA437E4040ED" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_284E04E849284192819CBA437E41A2E7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_723AB8AC878A7068EC8ABA437E41FB3A" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_ECAB2CC1791CA5F69A02BA437E4040ED" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_723AB8AC878A7068EC8ABA437E41FB3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_4F7BE1618C759329227EBA437E41399C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_ECAB2CC1791CA5F69A02BA437E4040ED" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_4F7BE1618C759329227EBA437E41399C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_9D3AA37F2A016C166FB90250966245AF" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_8F14466DCE2B6B2EA731025096603BAF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_9D3AA37F2A016C166FB90250966245AF" xlink:to="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_8F14466DCE2B6B2EA731025096603BAF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_6FEAEC70B42FC07D91A602509660B749" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_8F14466DCE2B6B2EA731025096603BAF" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_6FEAEC70B42FC07D91A602509660B749" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_7CA85796DBAE3FDE4EFD025096603CB5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_6FEAEC70B42FC07D91A602509660B749" xlink:to="loc_us-gaap_SegmentDomain_7CA85796DBAE3FDE4EFD025096603CB5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_7CA85796DBAE3FDE4EFD025096603CB5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_6FEAEC70B42FC07D91A602509660B749" xlink:to="loc_us-gaap_SegmentDomain_7CA85796DBAE3FDE4EFD025096603CB5" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_87E89E26DCDA96CB10E0025096618891" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_7CA85796DBAE3FDE4EFD025096603CB5" xlink:to="loc_clh_SafetyKleenMember_87E89E26DCDA96CB10E0025096618891" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsegmentsAxis" xlink:label="loc_us-gaap_SubsegmentsAxis_258CA00B6EE9A687BCD3025096614795" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_8F14466DCE2B6B2EA731025096603BAF" xlink:to="loc_us-gaap_SubsegmentsAxis_258CA00B6EE9A687BCD3025096614795" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsegmentsDomain" xlink:label="loc_us-gaap_SubsegmentsDomain_1CF1F90EC94DFFCA680B025096623248_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_258CA00B6EE9A687BCD3025096614795" xlink:to="loc_us-gaap_SubsegmentsDomain_1CF1F90EC94DFFCA680B025096623248_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsegmentsDomain" xlink:label="loc_us-gaap_SubsegmentsDomain_1CF1F90EC94DFFCA680B025096623248" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_258CA00B6EE9A687BCD3025096614795" xlink:to="loc_us-gaap_SubsegmentsDomain_1CF1F90EC94DFFCA680B025096623248" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LodgingSegmentMember" xlink:label="loc_clh_LodgingSegmentMember_8614359B725BF0400CA202509662CE6A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_1CF1F90EC94DFFCA680B025096623248" xlink:to="loc_clh_LodgingSegmentMember_8614359B725BF0400CA202509662CE6A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_88C39B66625A25D92A86025096623C7F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_9D3AA37F2A016C166FB90250966245AF" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_88C39B66625A25D92A86025096623C7F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_1BE48DB3C9FF206BFA5C02509663ED50" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_9D3AA37F2A016C166FB90250966245AF" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_1BE48DB3C9FF206BFA5C02509663ED50" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_F94CBFD7FC5935ACA38002509663B5D6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_9D3AA37F2A016C166FB90250966245AF" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_F94CBFD7FC5935ACA38002509663B5D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_35DB8934F47ABAAB722402509663E585" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_9D3AA37F2A016C166FB90250966245AF" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_35DB8934F47ABAAB722402509663E585" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiaries" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesBalanceSheetDetails" xlink:type="extended">
    <link:loc xlink:href="clh-20181231.xsd#clh_CondensedConsolidatingBalanceSheetLineItems" xlink:label="loc_clh_CondensedConsolidatingBalanceSheetLineItems_FCC0FBEA1194CED2BD7A712498979560" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_srt_ScheduleOfCondensedFinancialStatementsTable_CFCBEA20D5F25B92F1AD7124989428B8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_clh_CondensedConsolidatingBalanceSheetLineItems_FCC0FBEA1194CED2BD7A712498979560" xlink:to="loc_srt_ScheduleOfCondensedFinancialStatementsTable_CFCBEA20D5F25B92F1AD7124989428B8" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_D146718A251A7F0E0B4D71249894B8BD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_CFCBEA20D5F25B92F1AD7124989428B8" xlink:to="loc_srt_ConsolidationItemsAxis_D146718A251A7F0E0B4D71249894B8BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_E0480ECCACDE30FBF0A4712498953B53_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_D146718A251A7F0E0B4D71249894B8BD" xlink:to="loc_srt_ConsolidationItemsDomain_E0480ECCACDE30FBF0A4712498953B53_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_E0480ECCACDE30FBF0A4712498953B53" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_D146718A251A7F0E0B4D71249894B8BD" xlink:to="loc_srt_ConsolidationItemsDomain_E0480ECCACDE30FBF0A4712498953B53" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ReportableLegalEntitiesMember" xlink:label="loc_srt_ReportableLegalEntitiesMember_B01153D51D8ACE2163ED712498957E41" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_E0480ECCACDE30FBF0A4712498953B53" xlink:to="loc_srt_ReportableLegalEntitiesMember_B01153D51D8ACE2163ED712498957E41" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationEliminationsMember" xlink:label="loc_srt_ConsolidationEliminationsMember_C2CB571806975888F2E07124989584A5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_E0480ECCACDE30FBF0A4712498953B53" xlink:to="loc_srt_ConsolidationEliminationsMember_C2CB571806975888F2E07124989584A5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidatedEntitiesAxis" xlink:label="loc_srt_ConsolidatedEntitiesAxis_89D876F9D691B73D3BEC712498964F19" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_CFCBEA20D5F25B92F1AD7124989428B8" xlink:to="loc_srt_ConsolidatedEntitiesAxis_89D876F9D691B73D3BEC712498964F19" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidatedEntitiesDomain" xlink:label="loc_srt_ConsolidatedEntitiesDomain_E6A81CCC735733B6729E7124989625EA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_89D876F9D691B73D3BEC712498964F19" xlink:to="loc_srt_ConsolidatedEntitiesDomain_E6A81CCC735733B6729E7124989625EA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidatedEntitiesDomain" xlink:label="loc_srt_ConsolidatedEntitiesDomain_E6A81CCC735733B6729E7124989625EA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_89D876F9D691B73D3BEC712498964F19" xlink:to="loc_srt_ConsolidatedEntitiesDomain_E6A81CCC735733B6729E7124989625EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ParentCompanyMember" xlink:label="loc_srt_ParentCompanyMember_18AE2A52D2023C60A3977124989634AE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_E6A81CCC735733B6729E7124989625EA" xlink:to="loc_srt_ParentCompanyMember_18AE2A52D2023C60A3977124989634AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_GuarantorSubsidiariesMember" xlink:label="loc_srt_GuarantorSubsidiariesMember_F48E04BE55DA5039A3E8712498975953" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_E6A81CCC735733B6729E7124989625EA" xlink:to="loc_srt_GuarantorSubsidiariesMember_F48E04BE55DA5039A3E8712498975953" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_NonGuarantorSubsidiariesMember" xlink:label="loc_srt_NonGuarantorSubsidiariesMember_B21E2FA711EAEA867740712498974549" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_E6A81CCC735733B6729E7124989625EA" xlink:to="loc_srt_NonGuarantorSubsidiariesMember_B21E2FA711EAEA867740712498974549" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingBalanceSheetLineItems_FCC0FBEA1194CED2BD7A712498979560" xlink:to="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_C1D0A7501603C05FACD071249898901F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_C1D0A7501603C05FACD071249898901F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_0BBE506ACA5B7D89EB127124989885E9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_0BBE506ACA5B7D89EB127124989885E9" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ReceivablesFromAffiliatesSubsidiariesAndHoldingCompanies" xlink:label="loc_clh_ReceivablesFromAffiliatesSubsidiariesAndHoldingCompanies_72340521E7F12E0EBCE67124989888AE" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_clh_ReceivablesFromAffiliatesSubsidiariesAndHoldingCompanies_72340521E7F12E0EBCE67124989888AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_F171DC8D25802A204DFB71249898EC46" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_F171DC8D25802A204DFB71249898EC46" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="loc_us-gaap_OtherAssetsCurrent_DA2D42B446F614F5E183712498993423" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_us-gaap_OtherAssetsCurrent_DA2D42B446F614F5E183712498993423" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_764E1EA5CC22C44532B6712498995542" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_764E1EA5CC22C44532B6712498995542" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures" xlink:label="loc_us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_B0111CC9B515AF9D95A871249899C349" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_B0111CC9B515AF9D95A871249899C349" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DebtReceivableFromAffiliatesSubsidiariesAndHoldingCompanies" xlink:label="loc_clh_DebtReceivableFromAffiliatesSubsidiariesAndHoldingCompanies_DE00DF92743CB4A9173B712498998336" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_clh_DebtReceivableFromAffiliatesSubsidiariesAndHoldingCompanies_DE00DF92743CB4A9173B712498998336" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_3CC166C176A5EE8867FE7124989ADA27" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_us-gaap_Goodwill_3CC166C176A5EE8867FE7124989ADA27" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_3171F8B196888E754E137124989A1B24" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_3171F8B196888E754E137124989A1B24" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DeferredFinancingCostsandOtherAssets" xlink:label="loc_clh_DeferredFinancingCostsandOtherAssets_FAA17E607D39A32DE16D7124989A74B6" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_clh_DeferredFinancingCostsandOtherAssets_FAA17E607D39A32DE16D7124989A74B6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_6ECFFB180EEBCE696C477124989A6E85" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_8EA8609271115B78DBD4712498987CB9" xlink:to="loc_us-gaap_Assets_6ECFFB180EEBCE696C477124989A6E85" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingBalanceSheetLineItems_FCC0FBEA1194CED2BD7A712498979560" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_C3FA340A6856DD90D0237124989AE9C3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:to="loc_us-gaap_LiabilitiesCurrent_C3FA340A6856DD90D0237124989AE9C3" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PayablesToAffiliatesSubsidiariesAndHoldingCompanies" xlink:label="loc_clh_PayablesToAffiliatesSubsidiariesAndHoldingCompanies_F52EE9C78CB00E7C98427124989BA6EE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:to="loc_clh_PayablesToAffiliatesSubsidiariesAndHoldingCompanies_F52EE9C78CB00E7C98427124989BA6EE" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ClosurePostClosureAndRemedialLiabilitiesNet" xlink:label="loc_clh_ClosurePostClosureAndRemedialLiabilitiesNet_EE5170DF12126B3B33AE7124989B14C4" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:to="loc_clh_ClosurePostClosureAndRemedialLiabilitiesNet_EE5170DF12126B3B33AE7124989B14C4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_CC23584FCA6BB3312B707124989BC3CD" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_CC23584FCA6BB3312B707124989BC3CD" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DebtPayableToAffiliatesSubsidiariesAndHoldingCompanies" xlink:label="loc_clh_DebtPayableToAffiliatesSubsidiariesAndHoldingCompanies_701D127743A4866A1EDF7124989B304B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:to="loc_clh_DebtPayableToAffiliatesSubsidiariesAndHoldingCompanies_701D127743A4866A1EDF7124989B304B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent" xlink:label="loc_clh_UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent_D9DA094427A21748D44A7124989C9326" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:to="loc_clh_UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent_D9DA094427A21748D44A7124989C9326" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_00313856913701EDE6277124989C43B8" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:to="loc_us-gaap_Liabilities_00313856913701EDE6277124989C43B8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_F81C3EE4555ACEB4ED31713AE9B196D1" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:to="loc_us-gaap_StockholdersEquity_F81C3EE4555ACEB4ED31713AE9B196D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_59E222EC03C3BB9CCB027124989C1B82" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_2268F36E6BE0A410E3F97124989AACC9" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_59E222EC03C3BB9CCB027124989C1B82" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesCashFlowsDetails" xlink:type="extended">
    <link:loc xlink:href="clh-20181231.xsd#clh_CondensedConsolidatingStatementsOfCashFlowsLineItems" xlink:label="loc_clh_CondensedConsolidatingStatementsOfCashFlowsLineItems_CD418AF59FF5C76E07D617969DD5FF1A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_srt_ScheduleOfCondensedFinancialStatementsTable_B8BB025972AD7F85C47C17969DD34B15" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_clh_CondensedConsolidatingStatementsOfCashFlowsLineItems_CD418AF59FF5C76E07D617969DD5FF1A" xlink:to="loc_srt_ScheduleOfCondensedFinancialStatementsTable_B8BB025972AD7F85C47C17969DD34B15" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_45F3AB1D48A404F5BCA817969DD37FEA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_B8BB025972AD7F85C47C17969DD34B15" xlink:to="loc_srt_ConsolidationItemsAxis_45F3AB1D48A404F5BCA817969DD37FEA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_014F85F2D551CFB8C4EB17969DD301C6_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_45F3AB1D48A404F5BCA817969DD37FEA" xlink:to="loc_srt_ConsolidationItemsDomain_014F85F2D551CFB8C4EB17969DD301C6_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_014F85F2D551CFB8C4EB17969DD301C6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_45F3AB1D48A404F5BCA817969DD37FEA" xlink:to="loc_srt_ConsolidationItemsDomain_014F85F2D551CFB8C4EB17969DD301C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ReportableLegalEntitiesMember" xlink:label="loc_srt_ReportableLegalEntitiesMember_FA54D27D6373340F343017969DD376A6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_014F85F2D551CFB8C4EB17969DD301C6" xlink:to="loc_srt_ReportableLegalEntitiesMember_FA54D27D6373340F343017969DD376A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationEliminationsMember" xlink:label="loc_srt_ConsolidationEliminationsMember_46DCED836E3AF8CAA0DF17969DD4BF11" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_014F85F2D551CFB8C4EB17969DD301C6" xlink:to="loc_srt_ConsolidationEliminationsMember_46DCED836E3AF8CAA0DF17969DD4BF11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidatedEntitiesAxis" xlink:label="loc_srt_ConsolidatedEntitiesAxis_FC0EF0278596C008A7FD17969DD4EEDF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_B8BB025972AD7F85C47C17969DD34B15" xlink:to="loc_srt_ConsolidatedEntitiesAxis_FC0EF0278596C008A7FD17969DD4EEDF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidatedEntitiesDomain" xlink:label="loc_srt_ConsolidatedEntitiesDomain_F39FBEB88CB548720D4617969DD45987_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_FC0EF0278596C008A7FD17969DD4EEDF" xlink:to="loc_srt_ConsolidatedEntitiesDomain_F39FBEB88CB548720D4617969DD45987_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidatedEntitiesDomain" xlink:label="loc_srt_ConsolidatedEntitiesDomain_F39FBEB88CB548720D4617969DD45987" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_FC0EF0278596C008A7FD17969DD4EEDF" xlink:to="loc_srt_ConsolidatedEntitiesDomain_F39FBEB88CB548720D4617969DD45987" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ParentCompanyMember" xlink:label="loc_srt_ParentCompanyMember_026C6784F3F4098DF28B17969DD4654F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_F39FBEB88CB548720D4617969DD45987" xlink:to="loc_srt_ParentCompanyMember_026C6784F3F4098DF28B17969DD4654F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_GuarantorSubsidiariesMember" xlink:label="loc_srt_GuarantorSubsidiariesMember_183D80CF8E29A5F0ECF817969DD539BA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_F39FBEB88CB548720D4617969DD45987" xlink:to="loc_srt_GuarantorSubsidiariesMember_183D80CF8E29A5F0ECF817969DD539BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_NonGuarantorSubsidiariesMember" xlink:label="loc_srt_NonGuarantorSubsidiariesMember_20E337CEEE7C349C662017969DD5CDFF" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_F39FBEB88CB548720D4617969DD45987" xlink:to="loc_srt_NonGuarantorSubsidiariesMember_20E337CEEE7C349C662017969DD5CDFF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_2D525D5DB69A47503A2017969DD56CA7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfCashFlowsLineItems_CD418AF59FF5C76E07D617969DD5FF1A" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_2D525D5DB69A47503A2017969DD56CA7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfCashFlowsLineItems_CD418AF59FF5C76E07D617969DD5FF1A" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_0EA05BA891656419536F17969DD651DB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_0EA05BA891656419536F17969DD651DB" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ProceedsFromSalesOfFixedAssetsAndAssetsHeldForSale" xlink:label="loc_clh_ProceedsFromSalesOfFixedAssetsAndAssetsHeldForSale_861ED3FC12976C60269A17969DD6EBDF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_clh_ProceedsFromSalesOfFixedAssetsAndAssetsHeldForSale_861ED3FC12976C60269A17969DD6EBDF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleOfLongtermInvestments" xlink:label="loc_us-gaap_ProceedsFromSaleOfLongtermInvestments_821F2478ABAAB5F4363617969DD66172" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_us-gaap_ProceedsFromSaleOfLongtermInvestments_821F2478ABAAB5F4363617969DD66172" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_0519986EEA39B0C33F4D17969DD6E3EA" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_0519986EEA39B0C33F4D17969DD6E3EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_2F888E95337703FAB7FE17969DD73F21" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_2F888E95337703FAB7FE17969DD73F21" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireIntangibleAssets" xlink:label="loc_us-gaap_PaymentsToAcquireIntangibleAssets_729FDC96CE91130DFD9D17969DD7FFE7" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_us-gaap_PaymentsToAcquireIntangibleAssets_729FDC96CE91130DFD9D17969DD7FFE7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_1A52453249A2B7D5D63317969DD7D88D" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_1A52453249A2B7D5D63317969DD7D88D" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_IntercompanyInvesting" xlink:label="loc_clh_IntercompanyInvesting_55869EA675FBFDEAAC0817969DD767BB" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_clh_IntercompanyInvesting_55869EA675FBFDEAAC0817969DD767BB" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_IntercompanyDebtInvesting" xlink:label="loc_clh_IntercompanyDebtInvesting_EC84B4877F60436C2D4717969DD79266" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_clh_IntercompanyDebtInvesting_EC84B4877F60436C2D4717969DD79266" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates" xlink:label="loc_us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates_58CE2C777B183246528817969DD716B2" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates_58CE2C777B183246528817969DD716B2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_C78DAA69C28561C3743117969DD8ED82" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_3934327615E56503E5C017969DD6537C" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_C78DAA69C28561C3743117969DD8ED82" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfCashFlowsLineItems_CD418AF59FF5C76E07D617969DD5FF1A" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInOutstandingChecksFinancingActivities" xlink:label="loc_us-gaap_IncreaseDecreaseInOutstandingChecksFinancingActivities_0DA75C54E7B507F3D5FE17969DD82676" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_IncreaseDecreaseInOutstandingChecksFinancingActivities_0DA75C54E7B507F3D5FE17969DD82676" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_1970C8853DEEABDF22C717969DD8C772" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_1970C8853DEEABDF22C717969DD8C772" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_A2945243B44D9821095417969DD83A22" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_A2945243B44D9821095417969DD83A22" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:label="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_4FF021DC999B1066341017969DD9E2C3" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_4FF021DC999B1066341017969DD9E2C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsOfFinancingCosts" xlink:label="loc_us-gaap_PaymentsOfFinancingCosts_9412EB8B44ADD1B4AD2117969DD961C6" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_PaymentsOfFinancingCosts_9412EB8B44ADD1B4AD2117969DD961C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_E6987EEF7F5381693DE217969DD9B3E1" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_E6987EEF7F5381693DE217969DD9B3E1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RepaymentsOfLongTermDebt" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_D27DD8EC4CCAC2110C1A17969DD965C1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_D27DD8EC4CCAC2110C1A17969DD965C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsOfDebtExtinguishmentCosts" xlink:label="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_FC2ABAB67F1F29FEB0C517969DDF69C3" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_FC2ABAB67F1F29FEB0C517969DDF69C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_B9823F48A742F271ECFA17BE0A702882" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_B9823F48A742F271ECFA17BE0A702882" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_78497F586E17916D410117BD73B6E5E6" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_78497F586E17916D410117BD73B6E5E6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_B33C7D68A09C0F2021CB17969DDF29DC" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_B33C7D68A09C0F2021CB17969DDF29DC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="loc_us-gaap_RepaymentsOfLinesOfCredit_44537AE9537B2F8BE7EB17969DDFDFB9" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_RepaymentsOfLinesOfCredit_44537AE9537B2F8BE7EB17969DDFDFB9" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_IntercompanyFinancing" xlink:label="loc_clh_IntercompanyFinancing_F3D8FA99F6A5D9A2017B17969DDFE75B" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_clh_IntercompanyFinancing_F3D8FA99F6A5D9A2017B17969DDFE75B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_IntercompanyDebtFinancing" xlink:label="loc_clh_IntercompanyDebtFinancing_BEF0695529BAA3A2A9D317969DE0C409" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_clh_IntercompanyDebtFinancing_BEF0695529BAA3A2A9D317969DE0C409" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_417614800932B5FD6DA517969DE0C455" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_05DF64A34AC870FE11CA17969DD89B54" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_417614800932B5FD6DA517969DE0C455" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_812E8A82B29DB614721417969DE0EDF7" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfCashFlowsLineItems_CD418AF59FF5C76E07D617969DD5FF1A" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_812E8A82B29DB614721417969DE0EDF7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_EBBEFFFF62AF83DCB7BF17969DE178A5" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfCashFlowsLineItems_CD418AF59FF5C76E07D617969DD5FF1A" xlink:to="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_EBBEFFFF62AF83DCB7BF17969DE178A5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_279AC14F37811819DD6317969DE1366D" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfCashFlowsLineItems_CD418AF59FF5C76E07D617969DD5FF1A" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_279AC14F37811819DD6317969DE1366D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesIncomeStatementDetails" xlink:type="extended">
    <link:loc xlink:href="clh-20181231.xsd#clh_CondensedConsolidatingStatementsOfOperationsLineItems" xlink:label="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_srt_ScheduleOfCondensedFinancialStatementsTable_B885EBA9C34437321AA511A89904459B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_srt_ScheduleOfCondensedFinancialStatementsTable_B885EBA9C34437321AA511A89904459B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_8258E6A613BD3C91659C11A89909CBA8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_B885EBA9C34437321AA511A89904459B" xlink:to="loc_srt_ProductOrServiceAxis_8258E6A613BD3C91659C11A89909CBA8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_42B0281D24C5071E6C9A11A8990A2A24_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_8258E6A613BD3C91659C11A89909CBA8" xlink:to="loc_srt_ProductsAndServicesDomain_42B0281D24C5071E6C9A11A8990A2A24_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_42B0281D24C5071E6C9A11A8990A2A24" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_8258E6A613BD3C91659C11A89909CBA8" xlink:to="loc_srt_ProductsAndServicesDomain_42B0281D24C5071E6C9A11A8990A2A24" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ServiceMember" xlink:label="loc_us-gaap_ServiceMember_3B01CA291669EA06FCBA11A8990A9B00" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_42B0281D24C5071E6C9A11A8990A2A24" xlink:to="loc_us-gaap_ServiceMember_3B01CA291669EA06FCBA11A8990A9B00" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProductMember" xlink:label="loc_us-gaap_ProductMember_C7F38D4CDDB8FC45FD0011A8990A574A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_42B0281D24C5071E6C9A11A8990A2A24" xlink:to="loc_us-gaap_ProductMember_C7F38D4CDDB8FC45FD0011A8990A574A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_1172940728F58AC7CF7A11A8990B8310" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_B885EBA9C34437321AA511A89904459B" xlink:to="loc_srt_ConsolidationItemsAxis_1172940728F58AC7CF7A11A8990B8310" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_B104BFEDE5FD9B17ABBA11A8990BB02A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_1172940728F58AC7CF7A11A8990B8310" xlink:to="loc_srt_ConsolidationItemsDomain_B104BFEDE5FD9B17ABBA11A8990BB02A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_B104BFEDE5FD9B17ABBA11A8990BB02A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_1172940728F58AC7CF7A11A8990B8310" xlink:to="loc_srt_ConsolidationItemsDomain_B104BFEDE5FD9B17ABBA11A8990BB02A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ReportableLegalEntitiesMember" xlink:label="loc_srt_ReportableLegalEntitiesMember_57355B9A3C643DA6594E11A8990B9E31" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_B104BFEDE5FD9B17ABBA11A8990BB02A" xlink:to="loc_srt_ReportableLegalEntitiesMember_57355B9A3C643DA6594E11A8990B9E31" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationEliminationsMember" xlink:label="loc_srt_ConsolidationEliminationsMember_23EBD4704517E806CB9311A8990B6AF9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_B104BFEDE5FD9B17ABBA11A8990BB02A" xlink:to="loc_srt_ConsolidationEliminationsMember_23EBD4704517E806CB9311A8990B6AF9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidatedEntitiesAxis" xlink:label="loc_srt_ConsolidatedEntitiesAxis_0257A98C4B376CA0AEE411A8990B07E2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_B885EBA9C34437321AA511A89904459B" xlink:to="loc_srt_ConsolidatedEntitiesAxis_0257A98C4B376CA0AEE411A8990B07E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidatedEntitiesDomain" xlink:label="loc_srt_ConsolidatedEntitiesDomain_9FC98985A9FFF52CDA6811A8990CF63B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_0257A98C4B376CA0AEE411A8990B07E2" xlink:to="loc_srt_ConsolidatedEntitiesDomain_9FC98985A9FFF52CDA6811A8990CF63B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidatedEntitiesDomain" xlink:label="loc_srt_ConsolidatedEntitiesDomain_9FC98985A9FFF52CDA6811A8990CF63B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_0257A98C4B376CA0AEE411A8990B07E2" xlink:to="loc_srt_ConsolidatedEntitiesDomain_9FC98985A9FFF52CDA6811A8990CF63B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ParentCompanyMember" xlink:label="loc_srt_ParentCompanyMember_4F4462BC666F47EA5CF711A8990CEE13" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_9FC98985A9FFF52CDA6811A8990CF63B" xlink:to="loc_srt_ParentCompanyMember_4F4462BC666F47EA5CF711A8990CEE13" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_GuarantorSubsidiariesMember" xlink:label="loc_srt_GuarantorSubsidiariesMember_E5185ACCB0B5F7B8ED3D11A8990C3A71" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_9FC98985A9FFF52CDA6811A8990CF63B" xlink:to="loc_srt_GuarantorSubsidiariesMember_E5185ACCB0B5F7B8ED3D11A8990C3A71" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_NonGuarantorSubsidiariesMember" xlink:label="loc_srt_NonGuarantorSubsidiariesMember_D3BEEB28D9E7FF85900211A8990CDCA5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_9FC98985A9FFF52CDA6811A8990CF63B" xlink:to="loc_srt_NonGuarantorSubsidiariesMember_D3BEEB28D9E7FF85900211A8990CDCA5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="loc_us-gaap_RevenuesAbstract_FE2D2F28EA24F267427211A8990D1DA8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_RevenuesAbstract_FE2D2F28EA24F267427211A8990D1DA8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_6430B174CE8ADEE1053611A8990D9397" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_FE2D2F28EA24F267427211A8990D1DA8" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_6430B174CE8ADEE1053611A8990D9397" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CostOfRevenueAbstract" xlink:label="loc_us-gaap_CostOfRevenueAbstract_145E64C9EDFCAB8836F911A8990DF4F9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_CostOfRevenueAbstract_145E64C9EDFCAB8836F911A8990DF4F9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_4D5EBABF69B2F7F34A0011A8990ECD4F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_145E64C9EDFCAB8836F911A8990DF4F9" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_4D5EBABF69B2F7F34A0011A8990ECD4F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_0B9ED29485397028EE1511A8990E77F0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_0B9ED29485397028EE1511A8990E77F0" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AccretionOfEnvironmentalLiabilities" xlink:label="loc_clh_AccretionOfEnvironmentalLiabilities_AF157A567B9D19BCE5A311A8990EDC3E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_clh_AccretionOfEnvironmentalLiabilities_AF157A567B9D19BCE5A311A8990EDC3E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_09DB354E09111C94EB2E11A8990E2CE1" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_09DB354E09111C94EB2E11A8990E2CE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_E821D6930677C5A31BC111A8990E7F6C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_E821D6930677C5A31BC111A8990E7F6C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_7EF5C86508B4A1DC225311A8990FA2B1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_OperatingIncomeLoss_7EF5C86508B4A1DC225311A8990FA2B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_D500966303EE7766284D11A8990F309F" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_D500966303EE7766284D11A8990F309F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_D7C7F4930A8594ACD2E611A8990F8BB5" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_D7C7F4930A8594ACD2E611A8990F8BB5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_8DFF4B2D186A826C78A411A8990F6D5F" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_8DFF4B2D186A826C78A411A8990F6D5F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_InterestExpenseNet" xlink:label="loc_clh_InterestExpenseNet_DBD64B8D7F4B1E13FB1711A8990FF515" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_clh_InterestExpenseNet_DBD64B8D7F4B1E13FB1711A8990FF515" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_IncomeLossFromAffiliatesSubsidiariesAndHoldingCompany" xlink:label="loc_clh_IncomeLossFromAffiliatesSubsidiariesAndHoldingCompany_4C7A8F040DA538CCB39311A8990FFF2B" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_clh_IncomeLossFromAffiliatesSubsidiariesAndHoldingCompany_4C7A8F040DA538CCB39311A8990FFF2B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NetInterestIncomeFromAffiliatesSubsidiariesAndHoldingCompany" xlink:label="loc_clh_NetInterestIncomeFromAffiliatesSubsidiariesAndHoldingCompany_1F9DEDC729E9036988C711A89910553F" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_clh_NetInterestIncomeFromAffiliatesSubsidiariesAndHoldingCompany_1F9DEDC729E9036988C711A89910553F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_F1C8FB31779E9307547A11A89910DE7B" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_F1C8FB31779E9307547A11A89910DE7B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_EDDD4B2073E8894AC91211A89910C631" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_EDDD4B2073E8894AC91211A89910C631" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_11B15F1C6BACC87A246411A89910BADD" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_NetIncomeLoss_11B15F1C6BACC87A246411A89910BADD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_EA8987B240D764F8F45811A8991074E3" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_EA8987B240D764F8F45811A8991074E3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_5F09BA2D21244DD8DC8211A8991181B7" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_CondensedConsolidatingStatementsOfOperationsLineItems_66CF973A15D4CF1E2BD811A8990D834C" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_5F09BA2D21244DD8DC8211A8991181B7" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/IncomeTaxes" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/IncomeTaxesAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_A911F849283A0919FD6A2BB160BBE312" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_A911F849283A0919FD6A2BB160BBE312" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_8EFA82689EE08FA7DA252BB160BC1C00" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_A911F849283A0919FD6A2BB160BBE312" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_8EFA82689EE08FA7DA252BB160BC1C00" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_CFA1CD3105E54B23336C2BB160BC6F55_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_8EFA82689EE08FA7DA252BB160BC1C00" xlink:to="loc_us-gaap_EquityComponentDomain_CFA1CD3105E54B23336C2BB160BC6F55_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_CFA1CD3105E54B23336C2BB160BC6F55" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_8EFA82689EE08FA7DA252BB160BC1C00" xlink:to="loc_us-gaap_EquityComponentDomain_CFA1CD3105E54B23336C2BB160BC6F55" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_660A6782A56FCE99CEA82BB160BCEF9E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_CFA1CD3105E54B23336C2BB160BC6F55" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_660A6782A56FCE99CEA82BB160BCEF9E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_5C199D482D1268E21DD62BB160BD8124" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_5C199D482D1268E21DD62BB160BD8124" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TaxCutsandJobsActof2017ChangeinTaxRateIncomeTaxExpenseBenefit" xlink:label="loc_clh_TaxCutsandJobsActof2017ChangeinTaxRateIncomeTaxExpenseBenefit_AF4B7FEC33F6A06EC2712BB160C232CC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_TaxCutsandJobsActof2017ChangeinTaxRateIncomeTaxExpenseBenefit_AF4B7FEC33F6A06EC2712BB160C232CC" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TaxCutsandJobsActof2017IncompleteAccountingChangeinTaxRateDeferredTaxLiabilityProvisionalIncomeTaxExpenseBenefit" xlink:label="loc_clh_TaxCutsandJobsActof2017IncompleteAccountingChangeinTaxRateDeferredTaxLiabilityProvisionalIncomeTaxExpenseBenefit_98099B62B8FD4829C8D42BB160C27A08" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_TaxCutsandJobsActof2017IncompleteAccountingChangeinTaxRateDeferredTaxLiabilityProvisionalIncomeTaxExpenseBenefit_98099B62B8FD4829C8D42BB160C27A08" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalIncomeTaxExpense" xlink:label="loc_clh_TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalIncomeTaxExpense_84E52DAB21A7ED272B962BB160C2C74F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_TaxCutsAndJobsActOf2017IncompleteAccountingTransitionTaxForAccumulatedForeignEarningsProvisionalIncomeTaxExpense_84E52DAB21A7ED272B962BB160C2C74F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TaxCutsandJobsActTransitionTaxforAccumulatedForeignEarningsIncomeTaxExpense" xlink:label="loc_clh_TaxCutsandJobsActTransitionTaxforAccumulatedForeignEarningsIncomeTaxExpense_2A106C0CD3C3A0EF9D282BB160C3BB9E" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_TaxCutsandJobsActTransitionTaxforAccumulatedForeignEarningsIncomeTaxExpense_2A106C0CD3C3A0EF9D282BB160C3BB9E" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TaxCutsandJobsActMeasurementPeriodAdjustmentTransitionTaxforAccumulatedForeignEarningsIncomeTaxExpenseBenefit" xlink:label="loc_clh_TaxCutsandJobsActMeasurementPeriodAdjustmentTransitionTaxforAccumulatedForeignEarningsIncomeTaxExpenseBenefit_8494A56970D6DA77889C2BB160C31781" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_TaxCutsandJobsActMeasurementPeriodAdjustmentTransitionTaxforAccumulatedForeignEarningsIncomeTaxExpenseBenefit_8494A56970D6DA77889C2BB160C31781" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TaxCutsandJobsActof2017ChangeinTaxRateDeferredTaxLiabilityIncomeTaxExpenseBenefit" xlink:label="loc_clh_TaxCutsandJobsActof2017ChangeinTaxRateDeferredTaxLiabilityIncomeTaxExpenseBenefit_384A4A969DB5B15117572BB160C3292B" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_TaxCutsandJobsActof2017ChangeinTaxRateDeferredTaxLiabilityIncomeTaxExpenseBenefit_384A4A969DB5B15117572BB160C3292B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TaxCutsandJobsActMeasurementPeriodAdjustmentDeferredTaxAssetIncomeTaxExpenseBenefit" xlink:label="loc_clh_TaxCutsandJobsActMeasurementPeriodAdjustmentDeferredTaxAssetIncomeTaxExpenseBenefit_3AB14E0A5DCC6D239BEB2BB160C3E22C" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_TaxCutsandJobsActMeasurementPeriodAdjustmentDeferredTaxAssetIncomeTaxExpenseBenefit_3AB14E0A5DCC6D239BEB2BB160C3E22C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TaxCutsandJobsActIncomeTaxExpenseBenefit" xlink:label="loc_clh_TaxCutsandJobsActIncomeTaxExpenseBenefit_DB8DAF7BEF75EA91749F2BB160C3188C" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_TaxCutsandJobsActIncomeTaxExpenseBenefit_DB8DAF7BEF75EA91749F2BB160C3188C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TaxCutsandJobsActMeasurementPeriodAdjustmentIncomeTaxExpenseBenefit" xlink:label="loc_clh_TaxCutsandJobsActMeasurementPeriodAdjustmentIncomeTaxExpenseBenefit_1AD86483A7A45F5873C62BB160C334F7" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_TaxCutsandJobsActMeasurementPeriodAdjustmentIncomeTaxExpenseBenefit_1AD86483A7A45F5873C62BB160C334F7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_B38DF95E5B90CFA5BFBB2BB160C4A126" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_B38DF95E5B90CFA5BFBB2BB160C4A126" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_42B2926E27C03DA256C32BB160C41958" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_42B2926E27C03DA256C32BB160C41958" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ValuationAllowanceAmountForeignTaxCredits" xlink:label="loc_clh_ValuationAllowanceAmountForeignTaxCredits_307A8E5B87D8958874B82BB160C40AAD" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_ValuationAllowanceAmountForeignTaxCredits_307A8E5B87D8958874B82BB160C40AAD" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ValuationAllowanceDeferredTaxAssetFederalNetOperatingLossCarryforwards" xlink:label="loc_clh_ValuationAllowanceDeferredTaxAssetFederalNetOperatingLossCarryforwards_2A93C42D632E83E89DA12BB160C44F00" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_ValuationAllowanceDeferredTaxAssetFederalNetOperatingLossCarryforwards_2A93C42D632E83E89DA12BB160C44F00" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ValuationAllowanceAmountStateNetOperatingLoss" xlink:label="loc_clh_ValuationAllowanceAmountStateNetOperatingLoss_9D872858FC22D8DBDA412BB160C458C5" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_ValuationAllowanceAmountStateNetOperatingLoss_9D872858FC22D8DBDA412BB160C458C5" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ValuationAllowanceAmountForeignNetOperatingLoss" xlink:label="loc_clh_ValuationAllowanceAmountForeignNetOperatingLoss_D916E17865C791135A1A2BB160C44F7B" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_ValuationAllowanceAmountForeignNetOperatingLoss_D916E17865C791135A1A2BB160C44F7B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ValuationAllowanceAmountDeferredTaxAssetsofSubsidiary" xlink:label="loc_clh_ValuationAllowanceAmountDeferredTaxAssetsofSubsidiary_F779B1FBA2FED4AB903D2BB160C520CE" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_ValuationAllowanceAmountDeferredTaxAssetsofSubsidiary_F779B1FBA2FED4AB903D2BB160C520CE" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ValuationAllowanceAmountDeferredTaxAssetsofSubsidiaryTax" xlink:label="loc_clh_ValuationAllowanceAmountDeferredTaxAssetsofSubsidiaryTax_DB5ACCD71C7FA7DF7CF62BB160C527B1" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_clh_ValuationAllowanceAmountDeferredTaxAssetsofSubsidiaryTax_DB5ACCD71C7FA7DF7CF62BB160C527B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_60691BF6E53E9F614D172BB160C5C186" xlink:type="locator" />
    <link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_60691BF6E53E9F614D172BB160C5C186" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_B5A173F146DA5E2A47612BB160C59672" xlink:type="locator" />
    <link:definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_B5A173F146DA5E2A47612BB160C59672" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_38B5A51A9366CF3A5EA32BB160C6EB2A" xlink:type="locator" />
    <link:definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_38B5A51A9366CF3A5EA32BB160C6EB2A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_660634974873DEFD5C132BB160C6FA9A" xlink:type="locator" />
    <link:definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_4EDFFA5BB261C8605E582BB160BCC373" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_660634974873DEFD5C132BB160C6FA9A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/IncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/IncomeTaxesProvisionForTaxExpenseDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/IncomeTaxesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/InventoriesAndSupplies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/InventoriesAndSuppliesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/InventoriesAndSuppliesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/Operations" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/PropertyPlantAndEquipment" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/PropertyPlantAndEquipmentDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_F59C0C80AD5617087343CEF2C44926D6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_8B9318083F936640D14BCEF2C4460686" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_F59C0C80AD5617087343CEF2C44926D6" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_8B9318083F936640D14BCEF2C4460686" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_DA7ABA6A290CEBCDC50ACEF2C447FCF2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_8B9318083F936640D14BCEF2C4460686" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_DA7ABA6A290CEBCDC50ACEF2C447FCF2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_DA7ABA6A290CEBCDC50ACEF2C447FCF2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_DA7ABA6A290CEBCDC50ACEF2C447FCF2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LandMember" xlink:label="loc_us-gaap_LandMember_E73C43ABA52F29DAAEEECEF2C447EF58" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:to="loc_us-gaap_LandMember_E73C43ABA52F29DAAEEECEF2C447EF58" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetRetirementObligationCostsMember" xlink:label="loc_us-gaap_AssetRetirementObligationCostsMember_4ADFCDFA78AA0AAE8940CEF2C448E3A3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:to="loc_us-gaap_AssetRetirementObligationCostsMember_4ADFCDFA78AA0AAE8940CEF2C448E3A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LandfillMember" xlink:label="loc_us-gaap_LandfillMember_699250EEE6F7D770B3D9CEF2C4481678" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:to="loc_us-gaap_LandfillMember_699250EEE6F7D770B3D9CEF2C4481678" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_6B33CB4846B930B620F9CEF2C4489105" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_6B33CB4846B930B620F9CEF2C4489105" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CampEquipmentMember" xlink:label="loc_clh_CampEquipmentMember_11ED5403903C92083613CEF2C4486837" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:to="loc_clh_CampEquipmentMember_11ED5403903C92083613CEF2C4486837" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VehiclesMember" xlink:label="loc_us-gaap_VehiclesMember_B0AC7D024D56CAB5B186CEF2C448B584" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:to="loc_us-gaap_VehiclesMember_B0AC7D024D56CAB5B186CEF2C448B584" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquipmentMember" xlink:label="loc_us-gaap_EquipmentMember_85C8C604F49C0F99A1B8CEF2C4497AEE" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:to="loc_us-gaap_EquipmentMember_85C8C604F49C0F99A1B8CEF2C4497AEE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_65D3B1F1A13A74DC4608CEF2C449C33B" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_65D3B1F1A13A74DC4608CEF2C449C33B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConstructionInProgressMember" xlink:label="loc_us-gaap_ConstructionInProgressMember_97A4A5DB472BAB6ACE65CEF2C449DC9A" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_EA10011F490259161BAFCEF2C4474E9B" xlink:to="loc_us-gaap_ConstructionInProgressMember_97A4A5DB472BAB6ACE65CEF2C449DC9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_381B8309A43C123BC85ACEF2C449B4E5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_F59C0C80AD5617087343CEF2C44926D6" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_381B8309A43C123BC85ACEF2C449B4E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_081F59EC41BCA4C92AF0CEF2C44A7606" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_F59C0C80AD5617087343CEF2C44926D6" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_081F59EC41BCA4C92AF0CEF2C44A7606" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_287BFB9F075A4248F9C0CEF2C44AC557" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_F59C0C80AD5617087343CEF2C44926D6" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_287BFB9F075A4248F9C0CEF2C44AC557" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedCapitalizedInterestCosts" xlink:label="loc_us-gaap_AccumulatedCapitalizedInterestCosts_84A43E8C0A12A3CF57C7CEF2C44A4B0E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_F59C0C80AD5617087343CEF2C44926D6" xlink:to="loc_us-gaap_AccumulatedCapitalizedInterestCosts_84A43E8C0A12A3CF57C7CEF2C44A4B0E" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DepreciationInclusiveofAmortization" xlink:label="loc_clh_DepreciationInclusiveofAmortization_C4A8324CEEA671915CE2CEF2C44A1989" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_F59C0C80AD5617087343CEF2C44926D6" xlink:to="loc_clh_DepreciationInclusiveofAmortization_C4A8324CEEA671915CE2CEF2C44A1989" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/PropertyPlantAndEquipmentTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/QuarterlyDataUnaudited" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/QuarterlyDataUnauditedDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/QuarterlyDataUnauditedTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RemedialLiabilities" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RemedialLiabilitiesAdditionalInformationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RemedialLiabilitiesAnticipatedPaymentsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RemedialLiabilitiesChangesInRemedialLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SiteContingencyLineItems" xlink:label="loc_us-gaap_SiteContingencyLineItems_46FF3871636434C731951796A0C6ADF5" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SiteContingencyTable" xlink:label="loc_us-gaap_SiteContingencyTable_EDB3FC2CD3A73FF051F21796A0C4BFCB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SiteContingencyLineItems_46FF3871636434C731951796A0C6ADF5" xlink:to="loc_us-gaap_SiteContingencyTable_EDB3FC2CD3A73FF051F21796A0C4BFCB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EnvironmentalRemediationSiteAxis" xlink:label="loc_us-gaap_EnvironmentalRemediationSiteAxis_8C93D83CF8AED4F7307F1796A0C5F0BF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SiteContingencyTable_EDB3FC2CD3A73FF051F21796A0C4BFCB" xlink:to="loc_us-gaap_EnvironmentalRemediationSiteAxis_8C93D83CF8AED4F7307F1796A0C5F0BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EnvironmentalRemediationSiteDomain" xlink:label="loc_us-gaap_EnvironmentalRemediationSiteDomain_D0DCCD296CD75ED8698B1796A0C5D40C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteAxis_8C93D83CF8AED4F7307F1796A0C5F0BF" xlink:to="loc_us-gaap_EnvironmentalRemediationSiteDomain_D0DCCD296CD75ED8698B1796A0C5D40C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EnvironmentalRemediationSiteDomain" xlink:label="loc_us-gaap_EnvironmentalRemediationSiteDomain_D0DCCD296CD75ED8698B1796A0C5D40C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteAxis_8C93D83CF8AED4F7307F1796A0C5F0BF" xlink:to="loc_us-gaap_EnvironmentalRemediationSiteDomain_D0DCCD296CD75ED8698B1796A0C5D40C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RemedialLiabilitiesForLandfillSitesMember" xlink:label="loc_clh_RemedialLiabilitiesForLandfillSitesMember_D9E3564DB9848D4AB3571796A0C5C5A2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_D0DCCD296CD75ED8698B1796A0C5D40C" xlink:to="loc_clh_RemedialLiabilitiesForLandfillSitesMember_D9E3564DB9848D4AB3571796A0C5C5A2" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RemedialLiabilitiesForInactiveSitesMember" xlink:label="loc_clh_RemedialLiabilitiesForInactiveSitesMember_A022B529691301E33B431796A0C69C64" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_D0DCCD296CD75ED8698B1796A0C5D40C" xlink:to="loc_clh_RemedialLiabilitiesForInactiveSitesMember_A022B529691301E33B431796A0C69C64" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember" xlink:label="loc_clh_RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember_5B982A346471BFBBDF281796A0C68819" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_D0DCCD296CD75ED8698B1796A0C5D40C" xlink:to="loc_clh_RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember_5B982A346471BFBBDF281796A0C68819" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesRollForward" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_560F364C298AF2CA5BA61796A0C6EB7A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_46FF3871636434C731951796A0C6ADF5" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_560F364C298AF2CA5BA61796A0C6EB7A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingencies" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingencies_43D926B38ED838A803351796A0C75B14" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_560F364C298AF2CA5BA61796A0C6EB7A" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingencies_43D926B38ED838A803351796A0C75B14" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AccrualforEnvironmentalLossContingenciesIncreaseDecreaseforAcquisitionsandDivestituresMeasurementPeriodAdjustmentfromPriorPeriodAcquisition" xlink:label="loc_clh_AccrualforEnvironmentalLossContingenciesIncreaseDecreaseforAcquisitionsandDivestituresMeasurementPeriodAdjustmentfromPriorPeriodAcquisition_603C419A4A75DF66B0CF1796A0C7E1CF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_560F364C298AF2CA5BA61796A0C6EB7A" xlink:to="loc_clh_AccrualforEnvironmentalLossContingenciesIncreaseDecreaseforAcquisitionsandDivestituresMeasurementPeriodAdjustmentfromPriorPeriodAcquisition_603C419A4A75DF66B0CF1796A0C7E1CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses_5AB6424F9B67F33FAF2C1796A0C7EB08" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_560F364C298AF2CA5BA61796A0C6EB7A" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses_5AB6424F9B67F33FAF2C1796A0C7EB08" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForRevisionInEstimates" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForRevisionInEstimates_010AA24988E4729A82251796A0C7D865" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_560F364C298AF2CA5BA61796A0C6EB7A" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForRevisionInEstimates_010AA24988E4729A82251796A0C7D865" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesPayments1" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1_93114912323653DE082C1796A0C7A08B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_560F364C298AF2CA5BA61796A0C6EB7A" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1_93114912323653DE082C1796A0C7A08B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther" xlink:label="loc_clh_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther_8A9C9C132A1BBAE9770A1796A0C8C1FB" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_560F364C298AF2CA5BA61796A0C6EB7A" xlink:to="loc_clh_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther_8A9C9C132A1BBAE9770A1796A0C8C1FB" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RemedialLiabilitiesEstimatesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SiteContingencyLineItems" xlink:label="loc_us-gaap_SiteContingencyLineItems_E72B9323411C325AAC54DFB3F1D03BFE" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SiteContingencyTable" xlink:label="loc_us-gaap_SiteContingencyTable_673AA99FF8D8F5FC610EDFB3F1CB88D2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SiteContingencyLineItems_E72B9323411C325AAC54DFB3F1D03BFE" xlink:to="loc_us-gaap_SiteContingencyTable_673AA99FF8D8F5FC610EDFB3F1CB88D2" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EnvironmentalExitCostByPropertyAxis" xlink:label="loc_us-gaap_EnvironmentalExitCostByPropertyAxis_646986F33BF3D60FA8AFDFB3F1CBE4EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SiteContingencyTable_673AA99FF8D8F5FC610EDFB3F1CB88D2" xlink:to="loc_us-gaap_EnvironmentalExitCostByPropertyAxis_646986F33BF3D60FA8AFDFB3F1CBE4EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EnvironmentalExitCostsNameOfPropertyDomain" xlink:label="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EnvironmentalExitCostByPropertyAxis_646986F33BF3D60FA8AFDFB3F1CBE4EE" xlink:to="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EnvironmentalExitCostsNameOfPropertyDomain" xlink:label="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EnvironmentalExitCostByPropertyAxis_646986F33BF3D60FA8AFDFB3F1CBE4EE" xlink:to="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ActiveLandfillFacilitiesMember" xlink:label="loc_clh_ActiveLandfillFacilitiesMember_7C414CBBF7B3972A5EB5DFB3F1CB3888" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:to="loc_clh_ActiveLandfillFacilitiesMember_7C414CBBF7B3972A5EB5DFB3F1CB3888" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_InactiveLandfillFacilitiesMember" xlink:label="loc_clh_InactiveLandfillFacilitiesMember_974146EB0E4C2408B828DFB3F1CCF66F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:to="loc_clh_InactiveLandfillFacilitiesMember_974146EB0E4C2408B828DFB3F1CCF66F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SuperfundLandfillSitesOwnedByThirdPartiesMember" xlink:label="loc_clh_SuperfundLandfillSitesOwnedByThirdPartiesMember_ED4CA09FDBDC358A6356DFB3F1CCFD44" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:to="loc_clh_SuperfundLandfillSitesOwnedByThirdPartiesMember_ED4CA09FDBDC358A6356DFB3F1CCFD44" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ClosedIncineratorAndLandfillMember" xlink:label="loc_clh_ClosedIncineratorAndLandfillMember_54D61DE6502671C8F86BDFB3F1CC410C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:to="loc_clh_ClosedIncineratorAndLandfillMember_54D61DE6502671C8F86BDFB3F1CC410C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ClosedIncineratorMember" xlink:label="loc_clh_ClosedIncineratorMember_2399B64F22CBE26B00EBDFB3F1CCFFFA" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:to="loc_clh_ClosedIncineratorMember_2399B64F22CBE26B00EBDFB3F1CCFFFA" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_IdledIncineratorAndLegalProceedingsMember" xlink:label="loc_clh_IdledIncineratorAndLegalProceedingsMember_4661E900A7567B7AE4D3DFB3F1CC00B1" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:to="loc_clh_IdledIncineratorAndLegalProceedingsMember_4661E900A7567B7AE4D3DFB3F1CC00B1" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_OperatingSolventRecyclingCenterMember" xlink:label="loc_clh_OperatingSolventRecyclingCenterMember_A8D9D4EF7231C3317D4EDFB3F1CDE4A9" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:to="loc_clh_OperatingSolventRecyclingCenterMember_A8D9D4EF7231C3317D4EDFB3F1CDE4A9" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AllOtherIncineratorsLandfillsWastwaterThreatmentFacilitiesAndServiceCentersMember" xlink:label="loc_clh_AllOtherIncineratorsLandfillsWastwaterThreatmentFacilitiesAndServiceCentersMember_FE6CC325CF37F6925017DFB3F1CD1547" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalExitCostsNameOfPropertyDomain_ED1CADEC973D4135FFD1DFB3F1CBDAAE" xlink:to="loc_clh_AllOtherIncineratorsLandfillsWastwaterThreatmentFacilitiesAndServiceCentersMember_FE6CC325CF37F6925017DFB3F1CD1547" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_560F3C12D2B73D5EF8C8DFB3F1CD2166" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SiteContingencyTable_673AA99FF8D8F5FC610EDFB3F1CB88D2" xlink:to="loc_srt_StatementGeographicalAxis_560F3C12D2B73D5EF8C8DFB3F1CD2166" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_EA0B61C67FA49AA0587BDFB3F1CD925E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_560F3C12D2B73D5EF8C8DFB3F1CD2166" xlink:to="loc_srt_SegmentGeographicalDomain_EA0B61C67FA49AA0587BDFB3F1CD925E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_EA0B61C67FA49AA0587BDFB3F1CD925E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_560F3C12D2B73D5EF8C8DFB3F1CD2166" xlink:to="loc_srt_SegmentGeographicalDomain_EA0B61C67FA49AA0587BDFB3F1CD925E" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_BatonRougeLaMember" xlink:label="loc_clh_BatonRougeLaMember_A72701E878A4A0D265DFDFB3F1CDF8DB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_EA0B61C67FA49AA0587BDFB3F1CD925E" xlink:to="loc_clh_BatonRougeLaMember_A72701E878A4A0D265DFDFB3F1CDF8DB" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_BridgeportNjMember" xlink:label="loc_clh_BridgeportNjMember_64510FDD60EC6AFA5E3EDFB3F1CE1522" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_EA0B61C67FA49AA0587BDFB3F1CD925E" xlink:to="loc_clh_BridgeportNjMember_64510FDD60EC6AFA5E3EDFB3F1CE1522" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_MercierQuebecMember" xlink:label="loc_clh_MercierQuebecMember_1615045293D57FC39E48DFB3F1CEAB86" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_EA0B61C67FA49AA0587BDFB3F1CD925E" xlink:to="loc_clh_MercierQuebecMember_1615045293D57FC39E48DFB3F1CEAB86" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LindenNewJerseyMember" xlink:label="loc_clh_LindenNewJerseyMember_00CBBE50903C95DFD69CDFB3F1CF6CAE" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_EA0B61C67FA49AA0587BDFB3F1CD925E" xlink:to="loc_clh_LindenNewJerseyMember_00CBBE50903C95DFD69CDFB3F1CF6CAE" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_VariousMember" xlink:label="loc_clh_VariousMember_41898907BE2B0C3DF9F0DFB3F1CFC54C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_EA0B61C67FA49AA0587BDFB3F1CD925E" xlink:to="loc_clh_VariousMember_41898907BE2B0C3DF9F0DFB3F1CFC54C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingenciesByNatureOfContingencyAxis" xlink:label="loc_clh_ContingenciesByNatureOfContingencyAxis_CA57D5BFE91EA1DC53CEDFB3F1CF89EC" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SiteContingencyTable_673AA99FF8D8F5FC610EDFB3F1CB88D2" xlink:to="loc_clh_ContingenciesByNatureOfContingencyAxis_CA57D5BFE91EA1DC53CEDFB3F1CF89EC" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_E4C25A82EA6FB014F1B5DFB3F1CFFF17_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_CA57D5BFE91EA1DC53CEDFB3F1CF89EC" xlink:to="loc_clh_ContingencyNatureDomain_E4C25A82EA6FB014F1B5DFB3F1CFFF17_default" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_E4C25A82EA6FB014F1B5DFB3F1CFFF17" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_CA57D5BFE91EA1DC53CEDFB3F1CF89EC" xlink:to="loc_clh_ContingencyNatureDomain_E4C25A82EA6FB014F1B5DFB3F1CFFF17" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LegalAndAdministrativeProceedingsMember" xlink:label="loc_clh_LegalAndAdministrativeProceedingsMember_280F9E8EFED1F3E9F805DFB3F1D091EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingencyNatureDomain_E4C25A82EA6FB014F1B5DFB3F1CFFF17" xlink:to="loc_clh_LegalAndAdministrativeProceedingsMember_280F9E8EFED1F3E9F805DFB3F1D091EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingencies" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingencies_0BF1655A3ED0D0DAFBC2DFB3F1D0BF27" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_E72B9323411C325AAC54DFB3F1D03BFE" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingencies_0BF1655A3ED0D0DAFBC2DFB3F1D0BF27" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AccrualForEnvironmentalLossContingenciesPercentOfTotal" xlink:label="loc_clh_AccrualForEnvironmentalLossContingenciesPercentOfTotal_ABCE8F4D71535C9E4C4BDFB3F1D0DA7E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_E72B9323411C325AAC54DFB3F1D03BFE" xlink:to="loc_clh_AccrualForEnvironmentalLossContingenciesPercentOfTotal_ABCE8F4D71535C9E4C4BDFB3F1D0DA7E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EnvironmentalExitCostsReasonablyPossibleAdditionalLoss" xlink:label="loc_us-gaap_EnvironmentalExitCostsReasonablyPossibleAdditionalLoss_2D8B9E82BC0502114F83DFB3F1D122B2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_E72B9323411C325AAC54DFB3F1D03BFE" xlink:to="loc_us-gaap_EnvironmentalExitCostsReasonablyPossibleAdditionalLoss_2D8B9E82BC0502114F83DFB3F1D122B2" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NumberOfFacilityByType" xlink:label="loc_clh_NumberOfFacilityByType_F3EF253C9B9BA5967B6ADFB3F1D10FCD" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_E72B9323411C325AAC54DFB3F1D03BFE" xlink:to="loc_clh_NumberOfFacilityByType_F3EF253C9B9BA5967B6ADFB3F1D10FCD" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RemedialLiabilitiesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/Revenues" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RevenuesContractBalancesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RevenuesDisaggregationOfRevenueDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_32F795024E8F728B774A265B53FD998D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_FB0BAD68C2F066F7D3CF265B53F59195" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_32F795024E8F728B774A265B53FD998D" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_FB0BAD68C2F066F7D3CF265B53F59195" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_384454237F789C773D45265B53F6EC88" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_FB0BAD68C2F066F7D3CF265B53F59195" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_384454237F789C773D45265B53F6EC88" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_C8EA325AE0F3391524B1265B53F62A7D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_384454237F789C773D45265B53F6EC88" xlink:to="loc_us-gaap_SegmentDomain_C8EA325AE0F3391524B1265B53F62A7D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_C8EA325AE0F3391524B1265B53F62A7D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_384454237F789C773D45265B53F6EC88" xlink:to="loc_us-gaap_SegmentDomain_C8EA325AE0F3391524B1265B53F62A7D" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_EnvironmentalServicesMember" xlink:label="loc_clh_EnvironmentalServicesMember_39F8E5DAFB7957B858B4265B53F64330" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_C8EA325AE0F3391524B1265B53F62A7D" xlink:to="loc_clh_EnvironmentalServicesMember_39F8E5DAFB7957B858B4265B53F64330" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_D6E0FD4C8293ED5A4EEE265B53F749FB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_C8EA325AE0F3391524B1265B53F62A7D" xlink:to="loc_clh_SafetyKleenMember_D6E0FD4C8293ED5A4EEE265B53F749FB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CorporateMember" xlink:label="loc_us-gaap_CorporateMember_E73C9553D524B55DA92F265B53F7945C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_C8EA325AE0F3391524B1265B53F62A7D" xlink:to="loc_us-gaap_CorporateMember_E73C9553D524B55DA92F265B53F7945C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_5F5D203A9DB0F6CEA286265B53F7ACCE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_FB0BAD68C2F066F7D3CF265B53F59195" xlink:to="loc_srt_ProductOrServiceAxis_5F5D203A9DB0F6CEA286265B53F7ACCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_5F5D203A9DB0F6CEA286265B53F7ACCE" xlink:to="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_5F5D203A9DB0F6CEA286265B53F7ACCE" xlink:to="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_TechnicalServicesMember" xlink:label="loc_clh_TechnicalServicesMember_D1DED91C345C6DC81C20265B53F8D1FE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C" xlink:to="loc_clh_TechnicalServicesMember_D1DED91C345C6DC81C20265B53F8D1FE" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_FieldandEmergencyResponseMember" xlink:label="loc_clh_FieldandEmergencyResponseMember_F35991421820A1099247265B53FA36F9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C" xlink:to="loc_clh_FieldandEmergencyResponseMember_F35991421820A1099247265B53FA36F9" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_IndustrialServicesMember" xlink:label="loc_clh_IndustrialServicesMember_7BBBE5D2933951898460265B53FB8A88" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C" xlink:to="loc_clh_IndustrialServicesMember_7BBBE5D2933951898460265B53FB8A88" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_OilGasandLodgingServicesMember" xlink:label="loc_clh_OilGasandLodgingServicesMember_5AF554B97A5D5B539388265B53FBB0D0" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C" xlink:to="loc_clh_OilGasandLodgingServicesMember_5AF554B97A5D5B539388265B53FBB0D0" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SafetlyKleenEnvironmentalServicesMember" xlink:label="loc_clh_SafetlyKleenEnvironmentalServicesMember_613F36866634A016490E265B53FB6741" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C" xlink:to="loc_clh_SafetlyKleenEnvironmentalServicesMember_613F36866634A016490E265B53FB6741" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_KleenPerformanceProductsMember" xlink:label="loc_clh_KleenPerformanceProductsMember_F6D5096ABCB15715C2B4265B53FB854B" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_FB9E650569CCECBEC4E2265B53F7AE6C" xlink:to="loc_clh_KleenPerformanceProductsMember_F6D5096ABCB15715C2B4265B53FB854B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_7B3E41CA7F7F332231B7265B53FCF511" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_FB0BAD68C2F066F7D3CF265B53F59195" xlink:to="loc_srt_StatementGeographicalAxis_7B3E41CA7F7F332231B7265B53FCF511" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_712A50A83DDC7BF04B9C265B53FC05E7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_7B3E41CA7F7F332231B7265B53FCF511" xlink:to="loc_srt_SegmentGeographicalDomain_712A50A83DDC7BF04B9C265B53FC05E7_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_712A50A83DDC7BF04B9C265B53FC05E7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_7B3E41CA7F7F332231B7265B53FCF511" xlink:to="loc_srt_SegmentGeographicalDomain_712A50A83DDC7BF04B9C265B53FC05E7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="loc_country_US_B61889D2FE62242069DA265B53FC0D85" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_712A50A83DDC7BF04B9C265B53FC05E7" xlink:to="loc_country_US_B61889D2FE62242069DA265B53FC0D85" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_CA" xlink:label="loc_country_CA_58783E3991008BD30E8F265B53FC6FE5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_712A50A83DDC7BF04B9C265B53FC05E7" xlink:to="loc_country_CA_58783E3991008BD30E8F265B53FC6FE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0C24F248A27E364E5AC7265B53FD205D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_32F795024E8F728B774A265B53FD998D" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0C24F248A27E364E5AC7265B53FD205D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RevenuesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_4C5E488A0976EECA3E9C025096C16A9C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_A3BFC39FBDF22D66E2A0025096C142FB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4C5E488A0976EECA3E9C025096C16A9C" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_A3BFC39FBDF22D66E2A0025096C142FB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_83C1273CB32CB335A299025096C12E5B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_A3BFC39FBDF22D66E2A0025096C142FB" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_83C1273CB32CB335A299025096C12E5B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_28C6117D2A855D76F320025096C18ED5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_83C1273CB32CB335A299025096C12E5B" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_28C6117D2A855D76F320025096C18ED5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_28C6117D2A855D76F320025096C18ED5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_83C1273CB32CB335A299025096C12E5B" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_28C6117D2A855D76F320025096C18ED5" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_VeoliaDivisionMember" xlink:label="loc_clh_VeoliaDivisionMember_7C8C93BBEF0FBECB5785025096C17D06" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_28C6117D2A855D76F320025096C18ED5" xlink:to="loc_clh_VeoliaDivisionMember_7C8C93BBEF0FBECB5785025096C17D06" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_919232A4E06024797EA9025096C1E0E5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4C5E488A0976EECA3E9C025096C16A9C" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_919232A4E06024797EA9025096C1E0E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_601094CE44454BF61A77025096C1B06A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4C5E488A0976EECA3E9C025096C16A9C" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_601094CE44454BF61A77025096C1B06A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RevenuesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ScheduleIiValuationAndQualifyingAccounts" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/ScheduleIiValuationAndQualifyingAccountsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_18D6BEE9FC7EB91C23F671E96C0FB42A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureTable" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_115A34AEF0D96689F54471E96C0DCBAD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_18D6BEE9FC7EB91C23F671E96C0FB42A" xlink:to="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_115A34AEF0D96689F54471E96C0DCBAD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_8B9B34304703EB0EF82371E96C0EF0AA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_115A34AEF0D96689F54471E96C0DCBAD" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_8B9B34304703EB0EF82371E96C0EF0AA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_04DBDD71E116743393E471E96C0E3F6D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_8B9B34304703EB0EF82371E96C0EF0AA" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_04DBDD71E116743393E471E96C0E3F6D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_04DBDD71E116743393E471E96C0E3F6D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_8B9B34304703EB0EF82371E96C0EF0AA" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_04DBDD71E116743393E471E96C0E3F6D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AllowanceForCreditLossMember" xlink:label="loc_us-gaap_AllowanceForCreditLossMember_890183C7FC1F1D98DC5171E96C0E1F01" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_04DBDD71E116743393E471E96C0E3F6D" xlink:to="loc_us-gaap_AllowanceForCreditLossMember_890183C7FC1F1D98DC5171E96C0E1F01" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SECSchedule1209AllowanceRevenueMember" xlink:label="loc_clh_SECSchedule1209AllowanceRevenueMember_EEA0397F88A72EC50C2971FFD0D20842" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_04DBDD71E116743393E471E96C0E3F6D" xlink:to="loc_clh_SECSchedule1209AllowanceRevenueMember_EEA0397F88A72EC50C2971FFD0D20842" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:label="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_3775812D0449A366BC8E71E96C0FB024" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_04DBDD71E116743393E471E96C0E3F6D" xlink:to="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_3775812D0449A366BC8E71E96C0FB024" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35B7B6C8068FA96517E371E96C0F0191" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_18D6BEE9FC7EB91C23F671E96C0FB42A" xlink:to="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35B7B6C8068FA96517E371E96C0F0191" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_E37BAAF810EBC9168AF571E96C0F189A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35B7B6C8068FA96517E371E96C0F0191" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_E37BAAF810EBC9168AF571E96C0F189A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_C2E0339027DE358FA17971E96C109779" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35B7B6C8068FA96517E371E96C0F0191" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_C2E0339027DE358FA17971E96C109779" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions_40FB1D2513D43D68285E71E96C1082E0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35B7B6C8068FA96517E371E96C0F0191" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions_40FB1D2513D43D68285E71E96C1082E0" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReporting" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingGeographicalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_0C0D9B99E0C682409ADF270FDBDCDA69" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_C0A0FF9330DAB534EC03270FDBDB5B6F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0C0D9B99E0C682409ADF270FDBDCDA69" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_C0A0FF9330DAB534EC03270FDBDB5B6F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_A369F8D18739FD5443952710058745AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_C0A0FF9330DAB534EC03270FDBDB5B6F" xlink:to="loc_srt_ConsolidationItemsAxis_A369F8D18739FD5443952710058745AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_9115EB88676C49FF5DD5271007D76BF0_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_A369F8D18739FD5443952710058745AC" xlink:to="loc_srt_ConsolidationItemsDomain_9115EB88676C49FF5DD5271007D76BF0_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_9115EB88676C49FF5DD5271007D76BF0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_A369F8D18739FD5443952710058745AC" xlink:to="loc_srt_ConsolidationItemsDomain_9115EB88676C49FF5DD5271007D76BF0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_7FA0D9B67EC92806D17027103590363E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_9115EB88676C49FF5DD5271007D76BF0" xlink:to="loc_us-gaap_OperatingSegmentsMember_7FA0D9B67EC92806D17027103590363E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_2746138DD47CD3D5BF1E270FDBDB1834" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_C0A0FF9330DAB534EC03270FDBDB5B6F" xlink:to="loc_srt_StatementGeographicalAxis_2746138DD47CD3D5BF1E270FDBDB1834" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_4CEBAA6F6048F6B4C085270FDBDB09BC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_2746138DD47CD3D5BF1E270FDBDB1834" xlink:to="loc_srt_SegmentGeographicalDomain_4CEBAA6F6048F6B4C085270FDBDB09BC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_4CEBAA6F6048F6B4C085270FDBDB09BC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_2746138DD47CD3D5BF1E270FDBDB1834" xlink:to="loc_srt_SegmentGeographicalDomain_4CEBAA6F6048F6B4C085270FDBDB09BC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="loc_country_US_35327AD329F6AF6FF82F270FDBDB185A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_4CEBAA6F6048F6B4C085270FDBDB09BC" xlink:to="loc_country_US_35327AD329F6AF6FF82F270FDBDB185A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_CA" xlink:label="loc_country_CA_2604C0CF71896FCB02C7270FDBDC0AE9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_4CEBAA6F6048F6B4C085270FDBDB09BC" xlink:to="loc_country_CA_2604C0CF71896FCB02C7270FDBDC0AE9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_8CCC7A41D7FE1C388D97270FDBDC49AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0C0D9B99E0C682409ADF270FDBDCDA69" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_8CCC7A41D7FE1C388D97270FDBDC49AC" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SegmentReportingInformationRevenuePercent" xlink:label="loc_clh_SegmentReportingInformationRevenuePercent_D4E79D0B799C5CE6B428270FDBDDFC9A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0C0D9B99E0C682409ADF270FDBDCDA69" xlink:to="loc_clh_SegmentReportingInformationRevenuePercent_D4E79D0B799C5CE6B428270FDBDDFC9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_47C01F2C5493F88965E5270FDBDD902B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0C0D9B99E0C682409ADF270FDBDCDA69" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_47C01F2C5493F88965E5270FDBDD902B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PropertyPlantAndEquipmentNetPercent" xlink:label="loc_clh_PropertyPlantAndEquipmentNetPercent_EEF0E247F191A159C9CA270FDBDDD9F1" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0C0D9B99E0C682409ADF270FDBDCDA69" xlink:to="loc_clh_PropertyPlantAndEquipmentNetPercent_EEF0E247F191A159C9CA270FDBDDD9F1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_58A65113324514499AD9270FDBDDFF05" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0C0D9B99E0C682409ADF270FDBDCDA69" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_58A65113324514499AD9270FDBDDFF05" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_IntangibleAssetsNetExcludingGoodwillPercent" xlink:label="loc_clh_IntangibleAssetsNetExcludingGoodwillPercent_8D887EF1BD3E5D70AAD9270FDBDDCC87" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0C0D9B99E0C682409ADF270FDBDCDA69" xlink:to="loc_clh_IntangibleAssetsNetExcludingGoodwillPercent_8D887EF1BD3E5D70AAD9270FDBDDCC87" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_406E6775C512D8F82C49270FDBDD8CAD" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_0C0D9B99E0C682409ADF270FDBDCDA69" xlink:to="loc_us-gaap_Assets_406E6775C512D8F82C49270FDBDD8CAD" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingSegmentAdditionalInformationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingSegmentInformationRevenuesEbitaAndReconciliationToConsolidatedStatementOfOperationsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_03480E2C10A235B1B72127104B7BEF3D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_03480E2C10A235B1B72127104B7BEF3D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsAxis" xlink:label="loc_srt_ConsolidationItemsAxis_D43F61BFC77D0D0DCFB527104B7C9131" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_03480E2C10A235B1B72127104B7BEF3D" xlink:to="loc_srt_ConsolidationItemsAxis_D43F61BFC77D0D0DCFB527104B7C9131" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_415B6283D02895C080C827104B7C278C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_D43F61BFC77D0D0DCFB527104B7C9131" xlink:to="loc_srt_ConsolidationItemsDomain_415B6283D02895C080C827104B7C278C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ConsolidationItemsDomain" xlink:label="loc_srt_ConsolidationItemsDomain_415B6283D02895C080C827104B7C278C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_D43F61BFC77D0D0DCFB527104B7C9131" xlink:to="loc_srt_ConsolidationItemsDomain_415B6283D02895C080C827104B7C278C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_9026222E020A744918E227104B7C922E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_415B6283D02895C080C827104B7C278C" xlink:to="loc_us-gaap_OperatingSegmentsMember_9026222E020A744918E227104B7C922E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntersegmentEliminationMember" xlink:label="loc_us-gaap_IntersegmentEliminationMember_A4B7E0463E656068684E27104B7D8466" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_415B6283D02895C080C827104B7C278C" xlink:to="loc_us-gaap_IntersegmentEliminationMember_A4B7E0463E656068684E27104B7D8466" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_7ED699DBE7039CFCD98527104B7D66E2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_415B6283D02895C080C827104B7C278C" xlink:to="loc_us-gaap_CorporateNonSegmentMember_7ED699DBE7039CFCD98527104B7D66E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_1EDE4571B9C0092718FA27104B7ED1D7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_03480E2C10A235B1B72127104B7BEF3D" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_1EDE4571B9C0092718FA27104B7ED1D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3A42CDCD8F0A3BA3E85127104B7EA886_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1EDE4571B9C0092718FA27104B7ED1D7" xlink:to="loc_us-gaap_SegmentDomain_3A42CDCD8F0A3BA3E85127104B7EA886_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3A42CDCD8F0A3BA3E85127104B7EA886" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1EDE4571B9C0092718FA27104B7ED1D7" xlink:to="loc_us-gaap_SegmentDomain_3A42CDCD8F0A3BA3E85127104B7EA886" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_EnvironmentalServicesMember" xlink:label="loc_clh_EnvironmentalServicesMember_0813BD70AE00653C6EB427104B7E2632" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3A42CDCD8F0A3BA3E85127104B7EA886" xlink:to="loc_clh_EnvironmentalServicesMember_0813BD70AE00653C6EB427104B7E2632" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_8F8F3D1B989FB5DB6DC027104B7EA174" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3A42CDCD8F0A3BA3E85127104B7EA886" xlink:to="loc_clh_SafetyKleenMember_8F8F3D1B989FB5DB6DC027104B7EA174" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_736936B6BB479CF66E2C27104B7F0D3F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3A42CDCD8F0A3BA3E85127104B7EA886" xlink:to="loc_us-gaap_CorporateNonSegmentMember_736936B6BB479CF66E2C27104B7F0D3F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CorporateMember" xlink:label="loc_us-gaap_CorporateMember_24E9C06FA2E9ADDC60AA27104B7FE469" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3A42CDCD8F0A3BA3E85127104B7EA886" xlink:to="loc_us-gaap_CorporateMember_24E9C06FA2E9ADDC60AA27104B7FE469" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1CD2B495DE9B7C8595E427104B807251" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_1CD2B495DE9B7C8595E427104B807251" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet" xlink:label="loc_clh_IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet_3F375CCCEA97D21C8CD527104B804FB1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:to="loc_clh_IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet_3F375CCCEA97D21C8CD527104B804FB1" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract" xlink:label="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:to="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AccretionOfEnvironmentalLiabilities" xlink:label="loc_clh_AccretionOfEnvironmentalLiabilities_7F6B35728C969E7DEA5B27104B80188A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:to="loc_clh_AccretionOfEnvironmentalLiabilities_7F6B35728C969E7DEA5B27104B80188A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_E32468DD0C3B65F0CE1C27104B81A0EE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_E32468DD0C3B65F0CE1C27104B81A0EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_89F04961128E34B633CD27104B81D322" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_89F04961128E34B633CD27104B81D322" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_1CF8FDD5935C974FC47227104B8198E8" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:to="loc_us-gaap_OperatingIncomeLoss_1CF8FDD5935C974FC47227104B8198E8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_75ACACA5F95B516B22B827104B82F826" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_75ACACA5F95B516B22B827104B82F826" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_BC202EFF4FF9CE4837AD27104B8209CE" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_BC202EFF4FF9CE4837AD27104B8209CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_DEEEB6D255B81ADCA57E27104B82D7ED" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_DEEEB6D255B81ADCA57E27104B82D7ED" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_InterestExpenseNet" xlink:label="loc_clh_InterestExpenseNet_E782CD26342858923E3E27104B82B4DA" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:to="loc_clh_InterestExpenseNet_E782CD26342858923E3E27104B82B4DA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_36FCB06ABE4F9A4B2B2027104B82A177" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract_8201C6713CBEDDD3CF5827104B805963" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_36FCB06ABE4F9A4B2B2027104B82A177" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_54A0A810BEDD8B34211F27104B83EBA8" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:to="loc_us-gaap_Assets_54A0A810BEDD8B34211F27104B83EBA8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_69511912798A61EC243B27104B83B4AF" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_69511912798A61EC243B27104B83B4AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_358138BF2FD124F01E2D27104B83EF15" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:to="loc_us-gaap_Goodwill_358138BF2FD124F01E2D27104B83EF15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_0498E76D8CC41E5049A827104B834170" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_0498E76D8CC41E5049A827104B834170" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsNetIncludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_CF0A6469E379796351A327104B841FF8" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_E122B2865030FF7FC4BB27104B7F16F3" xlink:to="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_CF0A6469E379796351A327104B841FF8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPolicies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesAdvertisingExpenseDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesCashCashEquivalentsAndUncashedChecksDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesCreditConcentrationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems_09F9771BB6844D63D94617715B4062EB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTable" xlink:label="loc_us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTable_C3DA7F73558031C6BDBD17715B3F5900" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems_09F9771BB6844D63D94617715B4062EB" xlink:to="loc_us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTable_C3DA7F73558031C6BDBD17715B3F5900" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_A79016E6E65A7CFFE09217715B3F0933" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTable_C3DA7F73558031C6BDBD17715B3F5900" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_A79016E6E65A7CFFE09217715B3F0933" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_81361E8A2431BE9CAABC17715B3FE77A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_A79016E6E65A7CFFE09217715B3F0933" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_81361E8A2431BE9CAABC17715B3FE77A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_81361E8A2431BE9CAABC17715B3FE77A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_A79016E6E65A7CFFE09217715B3F0933" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_81361E8A2431BE9CAABC17715B3FE77A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsReceivableMember" xlink:label="loc_us-gaap_AccountsReceivableMember_93775F6BB9C0DFC3597317715B3F6821" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_81361E8A2431BE9CAABC17715B3FE77A" xlink:to="loc_us-gaap_AccountsReceivableMember_93775F6BB9C0DFC3597317715B3F6821" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SalesMember" xlink:label="loc_us-gaap_SalesMember_2026696245E0BD04A51417715B40DB8F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_81361E8A2431BE9CAABC17715B3FE77A" xlink:to="loc_us-gaap_SalesMember_2026696245E0BD04A51417715B40DB8F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ConcentrationRiskNumberofMajorCustomersOverBenchmark" xlink:label="loc_clh_ConcentrationRiskNumberofMajorCustomersOverBenchmark_AD3F1A1872F81D0D594B17715B40E37B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems_09F9771BB6844D63D94617715B4062EB" xlink:to="loc_clh_ConcentrationRiskNumberofMajorCustomersOverBenchmark_AD3F1A1872F81D0D594B17715B40E37B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ConcentrationRiskMajorCustomersOverBenchmark" xlink:label="loc_clh_ConcentrationRiskMajorCustomersOverBenchmark_CB22D36ADD43A56DDA2017715B407473" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems_09F9771BB6844D63D94617715B4062EB" xlink:to="loc_clh_ConcentrationRiskMajorCustomersOverBenchmark_CB22D36ADD43A56DDA2017715B407473" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesGoodwillAndIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_3EA8A9D8C31CC2E800D1568A2509ACA7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6936B509C41B72BFCBDB568A250781D0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_3EA8A9D8C31CC2E800D1568A2509ACA7" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6936B509C41B72BFCBDB568A250781D0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_A117A592A1666814D363568A2507882E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6936B509C41B72BFCBDB568A250781D0" xlink:to="loc_srt_RangeAxis_A117A592A1666814D363568A2507882E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_D72505208B3252680B7A568A250758EF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_A117A592A1666814D363568A2507882E" xlink:to="loc_srt_RangeMember_D72505208B3252680B7A568A250758EF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_D72505208B3252680B7A568A250758EF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_A117A592A1666814D363568A2507882E" xlink:to="loc_srt_RangeMember_D72505208B3252680B7A568A250758EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_20A3E5F16BDE66561490568A2508D9BA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_D72505208B3252680B7A568A250758EF" xlink:to="loc_srt_MinimumMember_20A3E5F16BDE66561490568A2508D9BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_C2E57D53833D7AC8E45D568A2508FA5C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_D72505208B3252680B7A568A250758EF" xlink:to="loc_srt_MaximumMember_C2E57D53833D7AC8E45D568A2508FA5C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_32723227250A37BF5008568A25085BBF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6936B509C41B72BFCBDB568A250781D0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_32723227250A37BF5008568A25085BBF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_091E8148F87BA71413F3568A25087CC8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_32723227250A37BF5008568A25085BBF" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_091E8148F87BA71413F3568A25087CC8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_091E8148F87BA71413F3568A25087CC8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_32723227250A37BF5008568A25085BBF" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_091E8148F87BA71413F3568A25087CC8" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PermitsMember" xlink:label="loc_clh_PermitsMember_1C03829CF177AD125048568A25097FDD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_091E8148F87BA71413F3568A25087CC8" xlink:to="loc_clh_PermitsMember_1C03829CF177AD125048568A25097FDD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherIntangibleAssetsMember" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_B841137E1BF3F6A18C28568A2509D9DF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_091E8148F87BA71413F3568A25087CC8" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_B841137E1BF3F6A18C28568A2509D9DF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_DC8F95BB8F945C2C6746568A2509234D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_3EA8A9D8C31CC2E800D1568A2509ACA7" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_DC8F95BB8F945C2C6746568A2509234D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesLandfillAccountingDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9C0E72DAF8E2EE4E2003A522DF750220" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9C0E72DAF8E2EE4E2003A522DF750220" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LongLivedAssetsByNameAxis" xlink:label="loc_clh_LongLivedAssetsByNameAxis_BAFB4FC990703668D363A522DF76AE64" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9C0E72DAF8E2EE4E2003A522DF750220" xlink:to="loc_clh_LongLivedAssetsByNameAxis_BAFB4FC990703668D363A522DF76AE64" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LongLivedAssetsByNameDomain" xlink:label="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_clh_LongLivedAssetsByNameAxis_BAFB4FC990703668D363A522DF76AE64" xlink:to="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707_default" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LongLivedAssetsByNameDomain" xlink:label="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_clh_LongLivedAssetsByNameAxis_BAFB4FC990703668D363A522DF76AE64" xlink:to="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AltairMember" xlink:label="loc_clh_AltairMember_B1F8A88C4AF961E982D4A522DF7685B1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_AltairMember_B1F8A88C4AF961E982D4A522DF7685B1" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ButtonwillowMember" xlink:label="loc_clh_ButtonwillowMember_2A95EEB6A8E96E19F4FEA522DF77B693" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_ButtonwillowMember_2A95EEB6A8E96E19F4FEA522DF77B693" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DeerParkMember" xlink:label="loc_clh_DeerParkMember_4F0A885333E37A129E55A522DF775020" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_DeerParkMember_4F0A885333E37A129E55A522DF775020" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_DeerTrailMember" xlink:label="loc_clh_DeerTrailMember_3A477148155DADADD8FAA522DF77DA4A" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_DeerTrailMember_3A477148155DADADD8FAA522DF77DA4A" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_GrassyMountainMember" xlink:label="loc_clh_GrassyMountainMember_8F09A96D9D0339350BA0A522DF77F8C9" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_GrassyMountainMember_8F09A96D9D0339350BA0A522DF77F8C9" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_KimballMember" xlink:label="loc_clh_KimballMember_BFFE8327D62FEB39DE12A522DF786BDF" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_KimballMember_BFFE8327D62FEB39DE12A522DF786BDF" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LambtonMember" xlink:label="loc_clh_LambtonMember_018B4571DCCEB693DBD3A522DF78E0C8" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_LambtonMember_018B4571DCCEB693DBD3A522DF78E0C8" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LoneMountainMember" xlink:label="loc_clh_LoneMountainMember_2338D3B07211F46A340DA522DF7849BD" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_LoneMountainMember_2338D3B07211F46A340DA522DF7849BD" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RyleyMember" xlink:label="loc_clh_RyleyMember_211499D7BE5FAA90DAF0A522DF787AC4" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_RyleyMember_211499D7BE5FAA90DAF0A522DF787AC4" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SawyerMember" xlink:label="loc_clh_SawyerMember_869339F202F008093056A522DF79319A" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_SawyerMember_869339F202F008093056A522DF79319A" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_WestmorlandMember" xlink:label="loc_clh_WestmorlandMember_54CBFE1CEB3F4C3CA441A522DF79C42B" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LongLivedAssetsByNameDomain_A54CBC2E8F3F914C8F2FA522DF76F707" xlink:to="loc_clh_WestmorlandMember_54CBFE1CEB3F4C3CA441A522DF79C42B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_97611EFBBD5BCA362B8EA522DF7966DA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9C0E72DAF8E2EE4E2003A522DF750220" xlink:to="loc_srt_StatementGeographicalAxis_97611EFBBD5BCA362B8EA522DF7966DA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_97611EFBBD5BCA362B8EA522DF7966DA" xlink:to="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_97611EFBBD5BCA362B8EA522DF7966DA" xlink:to="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd#stpr_TX" xlink:label="loc_stpr_TX_D371CBEE5226A8A8FA52A522DF7AF2FF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:to="loc_stpr_TX_D371CBEE5226A8A8FA52A522DF7AF2FF" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd#stpr_CA" xlink:label="loc_stpr_CA_BB2F818CB9EB1A9CEAA1A522DF7AAF9E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:to="loc_stpr_CA_BB2F818CB9EB1A9CEAA1A522DF7AAF9E" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd#stpr_CO" xlink:label="loc_stpr_CO_83702E2B890B6016B5E0A522DF7AD4D7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:to="loc_stpr_CO_83702E2B890B6016B5E0A522DF7AD4D7" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd#stpr_UT" xlink:label="loc_stpr_UT_4042AE57A3A8DCFA25AFA522DF7B34DF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:to="loc_stpr_UT_4042AE57A3A8DCFA25AFA522DF7B34DF" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd#stpr_NE" xlink:label="loc_stpr_NE_8EFBCC164303E0125CEBA522DF7BF388" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:to="loc_stpr_NE_8EFBCC164303E0125CEBA522DF7BF388" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd#stpr_CA-ON" xlink:label="loc_stpr_CA-ON_555BBB9EF170D72CEBACA522DF7B2FAE" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:to="loc_stpr_CA-ON_555BBB9EF170D72CEBACA522DF7B2FAE" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd#stpr_OK" xlink:label="loc_stpr_OK_D527C0560125D53EE1B2A522DF7C44AD" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:to="loc_stpr_OK_D527C0560125D53EE1B2A522DF7C44AD" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd#stpr_CA-AB" xlink:label="loc_stpr_CA-AB_9AD014999F22BA7B1A2AA522DF7C3019" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:to="loc_stpr_CA-AB_9AD014999F22BA7B1A2AA522DF7C3019" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd#stpr_ND" xlink:label="loc_stpr_ND_9DD464078E0215D2306FA522DF7CA2F7" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3337C378A0D0CDA8B154A522DF7ADA5C" xlink:to="loc_stpr_ND_9DD464078E0215D2306FA522DF7CA2F7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_DFE3A95E67AE70DCEB47A522DF7CBF50" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9C0E72DAF8E2EE4E2003A522DF750220" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_DFE3A95E67AE70DCEB47A522DF7CBF50" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9C94BD3E67B612238585A522DF7CE7B0_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_DFE3A95E67AE70DCEB47A522DF7CBF50" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9C94BD3E67B612238585A522DF7CE7B0_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9C94BD3E67B612238585A522DF7CE7B0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_DFE3A95E67AE70DCEB47A522DF7CBF50" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9C94BD3E67B612238585A522DF7CE7B0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LandfillMember" xlink:label="loc_us-gaap_LandfillMember_881C7356AA286E865537A522DF7D582A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9C94BD3E67B612238585A522DF7CE7B0" xlink:to="loc_us-gaap_LandfillMember_881C7356AA286E865537A522DF7D582A" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NonCommercialLandfillsMember" xlink:label="loc_clh_NonCommercialLandfillsMember_D93CA654AAFC908742B8A522DF7E6E91" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9C94BD3E67B612238585A522DF7CE7B0" xlink:to="loc_clh_NonCommercialLandfillsMember_D93CA654AAFC908742B8A522DF7E6E91" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PermittedMember" xlink:label="loc_clh_PermittedMember_B21AF5DF38853BBC855AA522DF809536" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9C94BD3E67B612238585A522DF7CE7B0" xlink:to="loc_clh_PermittedMember_B21AF5DF38853BBC855AA522DF809536" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_UnpermittedMember" xlink:label="loc_clh_UnpermittedMember_3F0FA295D0963069BBBDA522DF81C094" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_9C94BD3E67B612238585A522DF7CE7B0" xlink:to="loc_clh_UnpermittedMember_3F0FA295D0963069BBBDA522DF81C094" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_142A9E43FEADD1DBC68CA522DF81911A" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9C0E72DAF8E2EE4E2003A522DF750220" xlink:to="loc_srt_RangeAxis_142A9E43FEADD1DBC68CA522DF81911A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_607ECECD99995B693034A522DF82249C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_142A9E43FEADD1DBC68CA522DF81911A" xlink:to="loc_srt_RangeMember_607ECECD99995B693034A522DF82249C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_607ECECD99995B693034A522DF82249C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_142A9E43FEADD1DBC68CA522DF81911A" xlink:to="loc_srt_RangeMember_607ECECD99995B693034A522DF82249C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_D096A82F7E7D82221A8AA522DF8215EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_607ECECD99995B693034A522DF82249C" xlink:to="loc_srt_MinimumMember_D096A82F7E7D82221A8AA522DF8215EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_8E1A1FB16B92F5B1733BA522DF82E211" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_607ECECD99995B693034A522DF82249C" xlink:to="loc_srt_MaximumMember_8E1A1FB16B92F5B1733BA522DF82E211" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdjustmentForAmortization" xlink:label="loc_us-gaap_AdjustmentForAmortization_D158F1796B710145752FA522DF83189A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_us-gaap_AdjustmentForAmortization_D158F1796B710145752FA522DF83189A" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ApprovalstoAcceptWasteMaximum" xlink:label="loc_clh_ApprovalstoAcceptWasteMaximum_73C2D130AC1EAE43A878A522DF83897C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_ApprovalstoAcceptWasteMaximum_73C2D130AC1EAE43A878A522DF83897C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NumberOfExpansions" xlink:label="loc_clh_NumberOfExpansions_B48C68CECA683BD33DB4A522DF848775" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_NumberOfExpansions_B48C68CECA683BD33DB4A522DF848775" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NumberOfServiceLocationsWithUnpermittedExpansion" xlink:label="loc_clh_NumberOfServiceLocationsWithUnpermittedExpansion_06BEF3C1A3E3706C99FDA522DF841F52" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_NumberOfServiceLocationsWithUnpermittedExpansion_06BEF3C1A3E3706C99FDA522DF841F52" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PercentageOfAirspaceRemaining" xlink:label="loc_clh_PercentageOfAirspaceRemaining_D47F7CA99CBDBFE68B9BA522DF849F84" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_PercentageOfAirspaceRemaining_D47F7CA99CBDBFE68B9BA522DF849F84" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LandfillSites" xlink:label="loc_clh_LandfillSites_0983E6D16ED002CA9F34A522DF84F750" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_LandfillSites_0983E6D16ED002CA9F34A522DF84F750" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_BFF11CE309D04E4193F0A522DF847280" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_BFF11CE309D04E4193F0A522DF847280" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RemainingHighlyProbableAirspace" xlink:label="loc_clh_RemainingHighlyProbableAirspace_0339233B80DB21212887A522DF84B00B" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_RemainingHighlyProbableAirspace_0339233B80DB21212887A522DF84B00B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PermittedButNotHighlyProbableAirspace" xlink:label="loc_clh_PermittedButNotHighlyProbableAirspace_83142C8A2EA2E8F9ACB3A522DF85B25D" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_PermittedButNotHighlyProbableAirspace_83142C8A2EA2E8F9ACB3A522DF85B25D" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RemainingAirspaceCapacityRollForward" xlink:label="loc_clh_RemainingAirspaceCapacityRollForward_E376313EA3580D84C1D9A522DF85AEC7" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_RemainingAirspaceCapacityRollForward_E376313EA3580D84C1D9A522DF85AEC7" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ProbableAirspace" xlink:label="loc_clh_ProbableAirspace_D94588DCB0A760523721A522DF85DD43" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_RemainingAirspaceCapacityRollForward_E376313EA3580D84C1D9A522DF85AEC7" xlink:to="loc_clh_ProbableAirspace_D94588DCB0A760523721A522DF85DD43" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ChangesInHighlyProbableAirspace" xlink:label="loc_clh_ChangesInHighlyProbableAirspace_8D87E2D38A3D41E5D135A522DF862ACC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_RemainingAirspaceCapacityRollForward_E376313EA3580D84C1D9A522DF85AEC7" xlink:to="loc_clh_ChangesInHighlyProbableAirspace_8D87E2D38A3D41E5D135A522DF862ACC" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_ConsumedAirspace" xlink:label="loc_clh_ConsumedAirspace_1AB93FE9A76DFFED48A3A522DF86349A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_RemainingAirspaceCapacityRollForward_E376313EA3580D84C1D9A522DF85AEC7" xlink:to="loc_clh_ConsumedAirspace_1AB93FE9A76DFFED48A3A522DF86349A" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_LandfillFinalClosureAndPostClosureLiabilities" xlink:label="loc_clh_LandfillFinalClosureAndPostClosureLiabilities_2D3AF43B49EA368E9635A522DF8621E8" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_LandfillFinalClosureAndPostClosureLiabilities_2D3AF43B49EA368E9635A522DF8621E8" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RegulatoryPostClosurePeriodForLandfill" xlink:label="loc_clh_RegulatoryPostClosurePeriodForLandfill_66199CC57FB5038A43AEA522DF86516D" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_RegulatoryPostClosurePeriodForLandfill_66199CC57FB5038A43AEA522DF86516D" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_InflationRate" xlink:label="loc_clh_InflationRate_C4207D2AFE7B1620AF3EA522DF86607B" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_InflationRate_C4207D2AFE7B1620AF3EA522DF86607B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AssetRetirementObligationsDiscountRate" xlink:label="loc_clh_AssetRetirementObligationsDiscountRate_166804EF0B4E5EA54B43A522DF87306C" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_AssetRetirementObligationsDiscountRate_166804EF0B4E5EA54B43A522DF87306C" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NonLandfillClosureAndPostClosureTermInYears" xlink:label="loc_clh_NonLandfillClosureAndPostClosureTermInYears_9CB941B0099F300061B0A522DF8711BC" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_NonLandfillClosureAndPostClosureTermInYears_9CB941B0099F300061B0A522DF8711BC" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_NonLandfillClosureAndPostClosureLiabilities" xlink:label="loc_clh_NonLandfillClosureAndPostClosureLiabilities_EA240B391717B4F57128A522DF8747CA" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_40DBCF968E1409F226DDA522DF834AC8" xlink:to="loc_clh_NonLandfillClosureAndPostClosureLiabilities_EA240B391717B4F57128A522DF8747CA" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesMarketableSecuritiesAndCashEquivalentsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MarketableSecuritiesLineItems" xlink:label="loc_us-gaap_MarketableSecuritiesLineItems_25421A0426DF6320AFD0029E37F47021" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MarketableSecuritiesTable" xlink:label="loc_us-gaap_MarketableSecuritiesTable_6B9335739E7C73AC83C0029E37F237A7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_25421A0426DF6320AFD0029E37F47021" xlink:to="loc_us-gaap_MarketableSecuritiesTable_6B9335739E7C73AC83C0029E37F237A7" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashAndCashEquivalentsAxis" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_715732DC995BD1675C22029E37F2832C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MarketableSecuritiesTable_6B9335739E7C73AC83C0029E37F237A7" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_715732DC995BD1675C22029E37F2832C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_8C99194B88610E6DA672029E37F2C3B9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_715732DC995BD1675C22029E37F2832C" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_8C99194B88610E6DA672029E37F2C3B9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_8C99194B88610E6DA672029E37F2C3B9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_715732DC995BD1675C22029E37F2832C" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_8C99194B88610E6DA672029E37F2C3B9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommercialPaperMember" xlink:label="loc_us-gaap_CommercialPaperMember_2A328DAC3091EAE5E50502B241FCC5AE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_8C99194B88610E6DA672029E37F2C3B9" xlink:to="loc_us-gaap_CommercialPaperMember_2A328DAC3091EAE5E50502B241FCC5AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="loc_us-gaap_FinancialInstrumentAxis_6568305FFE847CBEB17B029E37F27329" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MarketableSecuritiesTable_6B9335739E7C73AC83C0029E37F237A7" xlink:to="loc_us-gaap_FinancialInstrumentAxis_6568305FFE847CBEB17B029E37F27329" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_BF826C9E9BB83C4F345A029E37F3AFCF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_6568305FFE847CBEB17B029E37F27329" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_BF826C9E9BB83C4F345A029E37F3AFCF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_BF826C9E9BB83C4F345A029E37F3AFCF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_6568305FFE847CBEB17B029E37F27329" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_BF826C9E9BB83C4F345A029E37F3AFCF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_E6C02912E587BA6E67AF029E37F398F9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_BF826C9E9BB83C4F345A029E37F3AFCF" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_E6C02912E587BA6E67AF029E37F398F9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_62752665130404B691F7029E37F3B37F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_BF826C9E9BB83C4F345A029E37F3AFCF" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_62752665130404B691F7029E37F3B37F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommercialMortgageBackedSecuritiesMember" xlink:label="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_EF8A774FE7A6424124F4029E37F4E9B5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_BF826C9E9BB83C4F345A029E37F3AFCF" xlink:to="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_EF8A774FE7A6424124F4029E37F4E9B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashEquivalentsAtCarryingValue_72868CBCC11785BF11AF029E37F5DBD9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_25421A0426DF6320AFD0029E37F47021" xlink:to="loc_us-gaap_CashEquivalentsAtCarryingValue_72868CBCC11785BF11AF029E37F5DBD9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_663B068101F33BDF00F3029E37F5CD5B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_25421A0426DF6320AFD0029E37F47021" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_663B068101F33BDF00F3029E37F5CD5B" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CashEquivalentsandMarketableSecuritiesCurrent" xlink:label="loc_clh_CashEquivalentsandMarketableSecuritiesCurrent_B3E042B878608E061AE2029E37F5F309" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_25421A0426DF6320AFD0029E37F47021" xlink:to="loc_clh_CashEquivalentsandMarketableSecuritiesCurrent_B3E042B878608E061AE2029E37F5F309" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesPolicies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesPropertyPlantAndEquipmentDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_47571F9C85EC1AE681A9024CF67A5710" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FFC6821010BA1266AB7B024CF66F48D9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_47571F9C85EC1AE681A9024CF67A5710" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FFC6821010BA1266AB7B024CF66F48D9" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_C60AB2C715904470A08F024CF66F2101" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FFC6821010BA1266AB7B024CF66F48D9" xlink:to="loc_srt_RangeAxis_C60AB2C715904470A08F024CF66F2101" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_48C803A28E22A65D5C36024CF66F269F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_C60AB2C715904470A08F024CF66F2101" xlink:to="loc_srt_RangeMember_48C803A28E22A65D5C36024CF66F269F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_48C803A28E22A65D5C36024CF66F269F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_C60AB2C715904470A08F024CF66F2101" xlink:to="loc_srt_RangeMember_48C803A28E22A65D5C36024CF66F269F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_94030F817A6AB92689F1024CF66F0DE8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_48C803A28E22A65D5C36024CF66F269F" xlink:to="loc_srt_MinimumMember_94030F817A6AB92689F1024CF66F0DE8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_A3D2A9305E80A9D17531024CF66F10BF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_48C803A28E22A65D5C36024CF66F269F" xlink:to="loc_srt_MaximumMember_A3D2A9305E80A9D17531024CF66F10BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_72586EFB3F295FE21F05024CF66FD7F7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FFC6821010BA1266AB7B024CF66F48D9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_72586EFB3F295FE21F05024CF66FD7F7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_72586EFB3F295FE21F05024CF66FD7F7" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_72586EFB3F295FE21F05024CF66FD7F7" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_37FA6B0ABDE2BF040E5C024CF66FF952" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:to="loc_us-gaap_BuildingMember_37FA6B0ABDE2BF040E5C024CF66FF952" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LandBuildingsAndImprovementsMember" xlink:label="loc_us-gaap_LandBuildingsAndImprovementsMember_7D2A1A51F41376268960024CF6741721" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:to="loc_us-gaap_LandBuildingsAndImprovementsMember_7D2A1A51F41376268960024CF6741721" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_CampEquipmentMember" xlink:label="loc_clh_CampEquipmentMember_E2A62E212AF28364EAB8024CF6748644" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:to="loc_clh_CampEquipmentMember_E2A62E212AF28364EAB8024CF6748644" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VehiclesMember" xlink:label="loc_us-gaap_VehiclesMember_20F5AFF40E727FAD58BF024CF674A1BF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:to="loc_us-gaap_VehiclesMember_20F5AFF40E727FAD58BF024CF674A1BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ComputerEquipmentMember" xlink:label="loc_us-gaap_ComputerEquipmentMember_C88201D7F37AAFEF323A024CF674F2BA" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:to="loc_us-gaap_ComputerEquipmentMember_C88201D7F37AAFEF323A024CF674F2BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RailroadTransportationEquipmentMember" xlink:label="loc_us-gaap_RailroadTransportationEquipmentMember_EFB803E4DD2EE76F3FCB024CF67428A0" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:to="loc_us-gaap_RailroadTransportationEquipmentMember_EFB803E4DD2EE76F3FCB024CF67428A0" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_AllOtherEquipmentMember" xlink:label="loc_clh_AllOtherEquipmentMember_18A1D3A9C519CBC7B78E024CF67AA395" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:to="loc_clh_AllOtherEquipmentMember_18A1D3A9C519CBC7B78E024CF67AA395" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_528ADF2A8B5AAE364488024CF67A26AB" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BDC3108867DEFA48EE45024CF66FDFBF" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_528ADF2A8B5AAE364488024CF67A26AB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_85346F9566EB945D75FC024CF67A59A2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_47571F9C85EC1AE681A9024CF67A5710" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_85346F9566EB945D75FC024CF67A59A2" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesRecentAccountingPronouncementsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_8B0ADC8C507EA46AF30117715B0568FD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95EB3E74BEF18070FEE717715B018E13" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_8B0ADC8C507EA46AF30117715B0568FD" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95EB3E74BEF18070FEE717715B018E13" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_1CF4BE82CF1386B5C93417715B012105" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95EB3E74BEF18070FEE717715B018E13" xlink:to="loc_us-gaap_StatementScenarioAxis_1CF4BE82CF1386B5C93417715B012105" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_E9C97015E9D1C4E64F1717715B01DF2A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_1CF4BE82CF1386B5C93417715B012105" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_E9C97015E9D1C4E64F1717715B01DF2A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_E9C97015E9D1C4E64F1717715B01DF2A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_1CF4BE82CF1386B5C93417715B012105" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_E9C97015E9D1C4E64F1717715B01DF2A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScenarioForecastMember" xlink:label="loc_us-gaap_ScenarioForecastMember_334B21726E3E0B7A439D17715B024537" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_E9C97015E9D1C4E64F1717715B01DF2A" xlink:to="loc_us-gaap_ScenarioForecastMember_334B21726E3E0B7A439D17715B024537" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_3E9F8C49D96289CE26BB17715B02728F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95EB3E74BEF18070FEE717715B018E13" xlink:to="loc_srt_RangeAxis_3E9F8C49D96289CE26BB17715B02728F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_DCB882E5A8481726926B17715B02E8A0_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_3E9F8C49D96289CE26BB17715B02728F" xlink:to="loc_srt_RangeMember_DCB882E5A8481726926B17715B02E8A0_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_DCB882E5A8481726926B17715B02E8A0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_3E9F8C49D96289CE26BB17715B02728F" xlink:to="loc_srt_RangeMember_DCB882E5A8481726926B17715B02E8A0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_3DA97589A7A4F12621CF17715B02D369" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_DCB882E5A8481726926B17715B02E8A0" xlink:to="loc_srt_MinimumMember_3DA97589A7A4F12621CF17715B02D369" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_0749D8942326E374A30717715B036010" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_DCB882E5A8481726926B17715B02E8A0" xlink:to="loc_srt_MaximumMember_0749D8942326E374A30717715B036010" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_7FDE14C0C0D9B9A2EA3617715B0308A2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95EB3E74BEF18070FEE717715B018E13" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_7FDE14C0C0D9B9A2EA3617715B0308A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_FC6B112DD8BDD48BF09717715B03839F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7FDE14C0C0D9B9A2EA3617715B0308A2" xlink:to="loc_us-gaap_EquityComponentDomain_FC6B112DD8BDD48BF09717715B03839F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_FC6B112DD8BDD48BF09717715B03839F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7FDE14C0C0D9B9A2EA3617715B0308A2" xlink:to="loc_us-gaap_EquityComponentDomain_FC6B112DD8BDD48BF09717715B03839F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_D714557984E968DD46F917715B03B6FD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_FC6B112DD8BDD48BF09717715B03839F" xlink:to="loc_us-gaap_RetainedEarningsMember_D714557984E968DD46F917715B03B6FD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E75DCEB344A3AE6BBADA17715B044136" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95EB3E74BEF18070FEE717715B018E13" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E75DCEB344A3AE6BBADA17715B044136" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_504F2FE684C86F64692C17715B04329E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E75DCEB344A3AE6BBADA17715B044136" xlink:to="loc_us-gaap_TypeOfAdoptionMember_504F2FE684C86F64692C17715B04329E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_504F2FE684C86F64692C17715B04329E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E75DCEB344A3AE6BBADA17715B044136" xlink:to="loc_us-gaap_TypeOfAdoptionMember_504F2FE684C86F64692C17715B04329E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountingStandardsUpdate201601Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201601Member_5EC46E2F3EA65E7E080917715B043E10" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_504F2FE684C86F64692C17715B04329E" xlink:to="loc_us-gaap_AccountingStandardsUpdate201601Member_5EC46E2F3EA65E7E080917715B043E10" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountingStandardsUpdate201616Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201616Member_573EFBB786E15B98194B17715B04B6C5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_504F2FE684C86F64692C17715B04329E" xlink:to="loc_us-gaap_AccountingStandardsUpdate201616Member_573EFBB786E15B98194B17715B04B6C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountingStandardsUpdate201602Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201602Member_F096254DF41F010FE61C17715B044370" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_504F2FE684C86F64692C17715B04329E" xlink:to="loc_us-gaap_AccountingStandardsUpdate201602Member_F096254DF41F010FE61C17715B044370" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_30709D41A344547D756017715B05D8FE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_8B0ADC8C507EA46AF30117715B0568FD" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_30709D41A344547D756017715B05D8FE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_D0B45A3EFD4DD6C3CAB717715B05EBAC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_8B0ADC8C507EA46AF30117715B0568FD" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_D0B45A3EFD4DD6C3CAB717715B05EBAC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_44A32EC406B97BA8BFCE17715B055A4E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_8B0ADC8C507EA46AF30117715B0568FD" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_44A32EC406B97BA8BFCE17715B055A4E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:label="loc_us-gaap_OperatingLeaseLiability_068247DAC951D316DEF217715B05B0DF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_8B0ADC8C507EA46AF30117715B0568FD" xlink:to="loc_us-gaap_OperatingLeaseLiability_068247DAC951D316DEF217715B05B0DF" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesRemedialLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RegulatoryLiabilitiesLineItems" xlink:label="loc_us-gaap_RegulatoryLiabilitiesLineItems_0C0D43E918CED33A81E81796A288DBA7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfRegulatoryLiabilitiesTable" xlink:label="loc_us-gaap_ScheduleOfRegulatoryLiabilitiesTable_5D79BC695A8D197F14801796A2872C65" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RegulatoryLiabilitiesLineItems_0C0D43E918CED33A81E81796A288DBA7" xlink:to="loc_us-gaap_ScheduleOfRegulatoryLiabilitiesTable_5D79BC695A8D197F14801796A2872C65" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_58160E07C9EEA9B4E6881796A2872D0E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRegulatoryLiabilitiesTable_5D79BC695A8D197F14801796A2872C65" xlink:to="loc_srt_RangeAxis_58160E07C9EEA9B4E6881796A2872D0E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_17955559F34877023E571796A28769A8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_58160E07C9EEA9B4E6881796A2872D0E" xlink:to="loc_srt_RangeMember_17955559F34877023E571796A28769A8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_17955559F34877023E571796A28769A8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_58160E07C9EEA9B4E6881796A2872D0E" xlink:to="loc_srt_RangeMember_17955559F34877023E571796A28769A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_2C7D712444F61B7658B51796A2880EAF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_17955559F34877023E571796A28769A8" xlink:to="loc_srt_MinimumMember_2C7D712444F61B7658B51796A2880EAF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_971CD3E735E7ABDE93151796A288C41E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_17955559F34877023E571796A28769A8" xlink:to="loc_srt_MaximumMember_971CD3E735E7ABDE93151796A288C41E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingencies" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingencies_BAC4AB8A6F2F49E026781796A2889B03" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilitiesLineItems_0C0D43E918CED33A81E81796A288DBA7" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingencies_BAC4AB8A6F2F49E026781796A2889B03" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PeriodOfTimeInYearsOverWhichBusinessAcquisitionsHaveBeenAcquired" xlink:label="loc_clh_PeriodOfTimeInYearsOverWhichBusinessAcquisitionsHaveBeenAcquired_13A5C9631EE5D131474A1796A289B19F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilitiesLineItems_0C0D43E918CED33A81E81796A288DBA7" xlink:to="loc_clh_PeriodOfTimeInYearsOverWhichBusinessAcquisitionsHaveBeenAcquired_13A5C9631EE5D131474A1796A289B19F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_SiteContingencyNumberOfSitesOwnedByEntity" xlink:label="loc_clh_SiteContingencyNumberOfSitesOwnedByEntity_E0DA798EC05AB66B1C2C1796A28903B0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilitiesLineItems_0C0D43E918CED33A81E81796A288DBA7" xlink:to="loc_clh_SiteContingencyNumberOfSitesOwnedByEntity_E0DA798EC05AB66B1C2C1796A28903B0" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RemedialLiabilitiesInflationRateatAcquisition" xlink:label="loc_clh_RemedialLiabilitiesInflationRateatAcquisition_A8CE89113F75BB9804291796A289F85F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilitiesLineItems_0C0D43E918CED33A81E81796A288DBA7" xlink:to="loc_clh_RemedialLiabilitiesInflationRateatAcquisition_A8CE89113F75BB9804291796A289F85F" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_RemedialLiabilitiesDiscountedRiskFreeInterestRate" xlink:label="loc_clh_RemedialLiabilitiesDiscountedRiskFreeInterestRate_ED8E3F4F5188B37518291796A289AFAA" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RegulatoryLiabilitiesLineItems_0C0D43E918CED33A81E81796A288DBA7" xlink:to="loc_clh_RemedialLiabilitiesDiscountedRiskFreeInterestRate_ED8E3F4F5188B37518291796A289AFAA" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlans" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlansPerformanceStockAwardsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80ADC8B559B6FD4AA69C3E0ECFC8776C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D20B761B188DADBA19D23E0ECFC71091" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80ADC8B559B6FD4AA69C3E0ECFC8776C" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D20B761B188DADBA19D23E0ECFC71091" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_47F3906BE7E1D8D074F43E0ECFC70861" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D20B761B188DADBA19D23E0ECFC71091" xlink:to="loc_us-gaap_AwardTypeAxis_47F3906BE7E1D8D074F43E0ECFC70861" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_418A3DA05ED14747D0A33E0ECFC818F2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_47F3906BE7E1D8D074F43E0ECFC70861" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_418A3DA05ED14747D0A33E0ECFC818F2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_418A3DA05ED14747D0A33E0ECFC818F2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_47F3906BE7E1D8D074F43E0ECFC70861" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_418A3DA05ED14747D0A33E0ECFC818F2" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PerformanceStockAwardsMember" xlink:label="loc_clh_PerformanceStockAwardsMember_91FB75B5D345EE7B8A073E0ECFC8D415" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_418A3DA05ED14747D0A33E0ECFC818F2" xlink:to="loc_clh_PerformanceStockAwardsMember_91FB75B5D345EE7B8A073E0ECFC8D415" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_PerformanceEvaluationStockBasedCompensation" xlink:label="loc_clh_PerformanceEvaluationStockBasedCompensation_328413654181CCACA8733E0ECFC9C7D2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80ADC8B559B6FD4AA69C3E0ECFC8776C" xlink:to="loc_clh_PerformanceEvaluationStockBasedCompensation_328413654181CCACA8733E0ECFC9C7D2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6D8BA3939C97C9A0B7573E0ECFC98AE0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80ADC8B559B6FD4AA69C3E0ECFC8776C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6D8BA3939C97C9A0B7573E0ECFC98AE0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_85AE665CA3BCC5B593563E0ECFCA364E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6D8BA3939C97C9A0B7573E0ECFC98AE0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_85AE665CA3BCC5B593563E0ECFCA364E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_F9027096D596E98795823E0ECFCA91D5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6D8BA3939C97C9A0B7573E0ECFC98AE0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_F9027096D596E98795823E0ECFCA91D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_8983EB77938D89EC92433E0ECFCB4529" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6D8BA3939C97C9A0B7573E0ECFC98AE0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_8983EB77938D89EC92433E0ECFCB4529" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_3B6B201E202A7E58D5A63E0ECFCB8C36" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6D8BA3939C97C9A0B7573E0ECFC98AE0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_3B6B201E202A7E58D5A63E0ECFCB8C36" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_373874E663E198437CE83E0ECFCD7704" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80ADC8B559B6FD4AA69C3E0ECFC8776C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_373874E663E198437CE83E0ECFCD7704" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_56FA8D048B9ABFB44F2F3E0ECFCE71B8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_373874E663E198437CE83E0ECFCD7704" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_56FA8D048B9ABFB44F2F3E0ECFCE71B8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_8159F9CA6800591CA3113E0ECFCEBA23" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_373874E663E198437CE83E0ECFCD7704" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_8159F9CA6800591CA3113E0ECFCEBA23" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_00A71DBDB46B279AACDA3E0ECFCE29D6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_373874E663E198437CE83E0ECFCD7704" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_00A71DBDB46B279AACDA3E0ECFCE29D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_2B557691D9BD5355BD7B3E0ECFCF5C1B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_373874E663E198437CE83E0ECFCD7704" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_2B557691D9BD5355BD7B3E0ECFCF5C1B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_4940D5BDB6166D0181C23E0ECFD0327B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80ADC8B559B6FD4AA69C3E0ECFC8776C" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_4940D5BDB6166D0181C23E0ECFD0327B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_94385E49E37B39038B193E0ECFD06F72" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80ADC8B559B6FD4AA69C3E0ECFC8776C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_94385E49E37B39038B193E0ECFD06F72" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlansRestrictedStockAwardsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A51225F76BEEED7D7E87BA1635478190" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E7DF6F741BA6C30DFEFEBA1635459D58" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A51225F76BEEED7D7E87BA1635478190" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E7DF6F741BA6C30DFEFEBA1635459D58" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_59F7B5AE4512C2DAA3D8BA1635451D10" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E7DF6F741BA6C30DFEFEBA1635459D58" xlink:to="loc_srt_RangeAxis_59F7B5AE4512C2DAA3D8BA1635451D10" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_AB2D11502598B744B3C2BA1635452B0B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_59F7B5AE4512C2DAA3D8BA1635451D10" xlink:to="loc_srt_RangeMember_AB2D11502598B744B3C2BA1635452B0B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_AB2D11502598B744B3C2BA1635452B0B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_59F7B5AE4512C2DAA3D8BA1635451D10" xlink:to="loc_srt_RangeMember_AB2D11502598B744B3C2BA1635452B0B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_A46BD9B7C874567F4D08BA1635465D7F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_AB2D11502598B744B3C2BA1635452B0B" xlink:to="loc_srt_MinimumMember_A46BD9B7C874567F4D08BA1635465D7F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_D000E2BD81AF5D51C169BA163546A6FB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_AB2D11502598B744B3C2BA1635452B0B" xlink:to="loc_srt_MaximumMember_D000E2BD81AF5D51C169BA163546A6FB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_03998ED086317CEBC2D5BA163546D7B4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E7DF6F741BA6C30DFEFEBA1635459D58" xlink:to="loc_us-gaap_AwardTypeAxis_03998ED086317CEBC2D5BA163546D7B4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_518FBCE7F548BF9DE271BA1635461471_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_03998ED086317CEBC2D5BA163546D7B4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_518FBCE7F548BF9DE271BA1635461471_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_518FBCE7F548BF9DE271BA1635461471" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_03998ED086317CEBC2D5BA163546D7B4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_518FBCE7F548BF9DE271BA1635461471" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_D47C0F33D367512A3396BA1635469582" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_518FBCE7F548BF9DE271BA1635461471" xlink:to="loc_us-gaap_RestrictedStockMember_D47C0F33D367512A3396BA1635469582" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_58C8F9740831D4D13EC4BA163547A606" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A51225F76BEEED7D7E87BA1635478190" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_58C8F9740831D4D13EC4BA163547A606" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_BC7A0C549FA1B5481B6CBA163547516B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A51225F76BEEED7D7E87BA1635478190" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_BC7A0C549FA1B5481B6CBA163547516B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_62E4922CE71622377B97BA163547D0EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_BC7A0C549FA1B5481B6CBA163547516B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_62E4922CE71622377B97BA163547D0EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_CD42B7A0E03871033E3DBA163548ADD0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_BC7A0C549FA1B5481B6CBA163547516B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_CD42B7A0E03871033E3DBA163548ADD0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_AAD2A0CFFF5CA1468586BA1635486559" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_BC7A0C549FA1B5481B6CBA163547516B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_AAD2A0CFFF5CA1468586BA1635486559" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_E2A296A8346DB85D5BECBA163548F61C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_BC7A0C549FA1B5481B6CBA163547516B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_E2A296A8346DB85D5BECBA163548F61C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_8CEF1E6C4F76ED8B2D4ABA1635482BA5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A51225F76BEEED7D7E87BA1635478190" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_8CEF1E6C4F76ED8B2D4ABA1635482BA5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_EEECBFA825FE2DC02197BA163549244D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_8CEF1E6C4F76ED8B2D4ABA1635482BA5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_EEECBFA825FE2DC02197BA163549244D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_0C339FC69D51D11B53D3BA1635491AA9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_8CEF1E6C4F76ED8B2D4ABA1635482BA5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_0C339FC69D51D11B53D3BA1635491AA9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_B125FC6491D8B52130D7BA163549D39E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_8CEF1E6C4F76ED8B2D4ABA1635482BA5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_B125FC6491D8B52130D7BA163549D39E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_AC1B314BC6B7D0A9CE75BA163549EA2E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_8CEF1E6C4F76ED8B2D4ABA1635482BA5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_AC1B314BC6B7D0A9CE75BA163549EA2E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_A560D38C6655BB4F3B60BA163549C6A2" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A51225F76BEEED7D7E87BA1635478190" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_A560D38C6655BB4F3B60BA163549C6A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_84A0BDF356A6AE700BFBBA16354A0417" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A51225F76BEEED7D7E87BA1635478190" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_84A0BDF356A6AE700BFBBA16354A0417" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_1241E373634E6C82610BBA16354AF71A" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A51225F76BEEED7D7E87BA1635478190" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_1241E373634E6C82610BBA16354AF71A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlansStockBasedCompensationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A77A5ED3610F166EE9B9BA163554740E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_98776CF8667845AEA2F8BA16355104F7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A77A5ED3610F166EE9B9BA163554740E" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_98776CF8667845AEA2F8BA16355104F7" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VestingAxis" xlink:label="loc_us-gaap_VestingAxis_6FC4DE0E1A69FA42D114BA163551A1AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_98776CF8667845AEA2F8BA16355104F7" xlink:to="loc_us-gaap_VestingAxis_6FC4DE0E1A69FA42D114BA163551A1AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VestingDomain" xlink:label="loc_us-gaap_VestingDomain_D5EF671AC8F03057149FBA16355165D5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_6FC4DE0E1A69FA42D114BA163551A1AC" xlink:to="loc_us-gaap_VestingDomain_D5EF671AC8F03057149FBA16355165D5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VestingDomain" xlink:label="loc_us-gaap_VestingDomain_D5EF671AC8F03057149FBA16355165D5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_6FC4DE0E1A69FA42D114BA163551A1AC" xlink:to="loc_us-gaap_VestingDomain_D5EF671AC8F03057149FBA16355165D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_BAF2347398339686E90CBA1635521A8C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_D5EF671AC8F03057149FBA16355165D5" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_BAF2347398339686E90CBA1635521A8C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_59ACB2E96FFFAA713E4EBA163552D7D1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_D5EF671AC8F03057149FBA16355165D5" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_59ACB2E96FFFAA713E4EBA163552D7D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_31513E747BA2B7EE82D6BA1635527F6B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_D5EF671AC8F03057149FBA16355165D5" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_31513E747BA2B7EE82D6BA1635527F6B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_D7783D52022C57329A80BA1635527A2E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_98776CF8667845AEA2F8BA16355104F7" xlink:to="loc_us-gaap_PlanNameAxis_D7783D52022C57329A80BA1635527A2E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_1C670810800C8DA3798EBA163552F366_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_D7783D52022C57329A80BA1635527A2E" xlink:to="loc_us-gaap_PlanNameDomain_1C670810800C8DA3798EBA163552F366_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_1C670810800C8DA3798EBA163552F366" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_D7783D52022C57329A80BA1635527A2E" xlink:to="loc_us-gaap_PlanNameDomain_1C670810800C8DA3798EBA163552F366" xlink:type="arc" />
    <link:loc xlink:href="clh-20181231.xsd#clh_A2010EquityIncentivePlanMember" xlink:label="loc_clh_A2010EquityIncentivePlanMember_E886AD35C400CD85D297BA163553505F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_1C670810800C8DA3798EBA163552F366" xlink:to="loc_clh_A2010EquityIncentivePlanMember_E886AD35C400CD85D297BA163553505F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_F55C9F11D89FC19965D8BA163553550B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_98776CF8667845AEA2F8BA16355104F7" xlink:to="loc_us-gaap_AwardTypeAxis_F55C9F11D89FC19965D8BA163553550B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81E4C23A526419CA0DD7BA1635533A67_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_F55C9F11D89FC19965D8BA163553550B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81E4C23A526419CA0DD7BA1635533A67_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81E4C23A526419CA0DD7BA1635533A67" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_F55C9F11D89FC19965D8BA163553550B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81E4C23A526419CA0DD7BA1635533A67" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_6A5C9FA311D086EE79E2BA163553A34D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_81E4C23A526419CA0DD7BA1635533A67" xlink:to="loc_us-gaap_RestrictedStockMember_6A5C9FA311D086EE79E2BA163553A34D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_EB7A24FEB68B019247B8BA16355421D6" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_98776CF8667845AEA2F8BA16355104F7" xlink:to="loc_srt_RangeAxis_EB7A24FEB68B019247B8BA16355421D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_4F12A231BA047F6DE7C8BA163554DBFD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_EB7A24FEB68B019247B8BA16355421D6" xlink:to="loc_srt_RangeMember_4F12A231BA047F6DE7C8BA163554DBFD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_4F12A231BA047F6DE7C8BA163554DBFD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_EB7A24FEB68B019247B8BA16355421D6" xlink:to="loc_srt_RangeMember_4F12A231BA047F6DE7C8BA163554DBFD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_FF5F4C9E63AA33505172BA163554EC3D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_4F12A231BA047F6DE7C8BA163554DBFD" xlink:to="loc_srt_MinimumMember_FF5F4C9E63AA33505172BA163554EC3D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_D5BB8B93989A8FAD0D20BA1635541398" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_4F12A231BA047F6DE7C8BA163554DBFD" xlink:to="loc_srt_MaximumMember_D5BB8B93989A8FAD0D20BA1635541398" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_A7BB48A14E083453E17EBA1635551A2C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A77A5ED3610F166EE9B9BA163554740E" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_A7BB48A14E083453E17EBA1635551A2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_135D1B3F5D1E3AA43E56BA1635558987" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A77A5ED3610F166EE9B9BA163554740E" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_135D1B3F5D1E3AA43E56BA1635558987" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_EF9A4BD8E3911F24FDA8BA163555937E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A77A5ED3610F166EE9B9BA163554740E" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_EF9A4BD8E3911F24FDA8BA163555937E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_07EBCC9E1186B7F98373BA163555BB71" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A77A5ED3610F166EE9B9BA163554740E" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_07EBCC9E1186B7F98373BA163555BB71" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockBasedCompensationAndEmployeeBenefitPlansTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockholdersEquity" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockholdersEquityDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:label="loc_us-gaap_ClassOfStockLineItems_4212E5AA2933B704FEB411D7CB7B5012" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_0F044CE0AB094B9B535C11D7CB7943AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_4212E5AA2933B704FEB411D7CB7B5012" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_0F044CE0AB094B9B535C11D7CB7943AC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_73F0C7F6096FF0354AF811D7CB7AE23C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_0F044CE0AB094B9B535C11D7CB7943AC" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_73F0C7F6096FF0354AF811D7CB7AE23C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_EED23F9E28DE0E8F380511D7CB7ADA9A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_73F0C7F6096FF0354AF811D7CB7AE23C" xlink:to="loc_us-gaap_EquityComponentDomain_EED23F9E28DE0E8F380511D7CB7ADA9A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_EED23F9E28DE0E8F380511D7CB7ADA9A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_73F0C7F6096FF0354AF811D7CB7AE23C" xlink:to="loc_us-gaap_EquityComponentDomain_EED23F9E28DE0E8F380511D7CB7ADA9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_ABD803E4C0AE3BC93FAA11D7CB7A0139" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_EED23F9E28DE0E8F380511D7CB7ADA9A" xlink:to="loc_us-gaap_CommonStockMember_ABD803E4C0AE3BC93FAA11D7CB7A0139" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_0E08B292727F9995A3C111D7CB7BE6EC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_EED23F9E28DE0E8F380511D7CB7ADA9A" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_0E08B292727F9995A3C111D7CB7BE6EC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_8CD2374126AD71240B1411D7CB7BF669" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_4212E5AA2933B704FEB411D7CB7B5012" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_8CD2374126AD71240B1411D7CB7BF669" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_9DAF9FF88D9A468C035B11D7CB7B07C6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_4212E5AA2933B704FEB411D7CB7B5012" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_9DAF9FF88D9A468C035B11D7CB7B07C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_94F322F87D1DB73E93D411D7CB7C0569" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_4212E5AA2933B704FEB411D7CB7B5012" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_94F322F87D1DB73E93D411D7CB7C0569" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_FE4608D988F48B55729411D7CB7C1006" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_4212E5AA2933B704FEB411D7CB7B5012" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_FE4608D988F48B55729411D7CB7C1006" xlink:type="arc" />
  </link:definitionLink>
</link:linkbase>