

<!--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-20190331.xsd#AccruedExpenses" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccruedExpensesDetails" xlink:href="clh-20190331.xsd#AccruedExpensesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccruedExpensesTables" xlink:href="clh-20190331.xsd#AccruedExpensesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLoss" xlink:href="clh-20190331.xsd#AccumulatedOtherComprehensiveLoss" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossChangesInAccumulatedOtherComprehensiveLossByComponentDetails" xlink:href="clh-20190331.xsd#AccumulatedOtherComprehensiveLossChangesInAccumulatedOtherComprehensiveLossByComponentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossReclassifiedOutOfAccumulatedOtherComprehensiveLossDetails" xlink:href="clh-20190331.xsd#AccumulatedOtherComprehensiveLossReclassifiedOutOfAccumulatedOtherComprehensiveLossDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossTables" xlink:href="clh-20190331.xsd#AccumulatedOtherComprehensiveLossTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BasisOfPresentation" xlink:href="clh-20190331.xsd#BasisOfPresentation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinations" xlink:href="clh-20190331.xsd#BusinessCombinations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinations2018AcquisitionsDetails" xlink:href="clh-20190331.xsd#BusinessCombinations2018AcquisitionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinations2019AcquisitionDetails" xlink:href="clh-20190331.xsd#BusinessCombinations2019AcquisitionDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinationsAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:href="clh-20190331.xsd#BusinessCombinationsAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/BusinessCombinationsTables" xlink:href="clh-20190331.xsd#BusinessCombinationsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilities" xlink:href="clh-20190331.xsd#ClosureAndPostClosureLiabilities" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilitiesDetails" xlink:href="clh-20190331.xsd#ClosureAndPostClosureLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ClosureAndPostClosureLiabilitiesTables" xlink:href="clh-20190331.xsd#ClosureAndPostClosureLiabilitiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/CommitmentsAndContingencies" xlink:href="clh-20190331.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/CommitmentsAndContingenciesDetails" xlink:href="clh-20190331.xsd#CommitmentsAndContingenciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedBalanceSheets" xlink:href="clh-20190331.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="clh-20190331.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/DocumentAndEntityInformation" xlink:href="clh-20190331.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/EarningsLossPerShare" xlink:href="clh-20190331.xsd#EarningsLossPerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/EarningsLossPerShareComputationOfBasicAndDilutedEarningsPerShareDetails" xlink:href="clh-20190331.xsd#EarningsLossPerShareComputationOfBasicAndDilutedEarningsPerShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/EarningsLossPerShareNarrativeDetails" xlink:href="clh-20190331.xsd#EarningsLossPerShareNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/EarningsLossPerShareTables" xlink:href="clh-20190331.xsd#EarningsLossPerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/FinancingArrangements" xlink:href="clh-20190331.xsd#FinancingArrangements" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/FinancingArrangementsNarrativeDetails" xlink:href="clh-20190331.xsd#FinancingArrangementsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/FinancingArrangementsSummaryOfFinancingArrangementsDetails" xlink:href="clh-20190331.xsd#FinancingArrangementsSummaryOfFinancingArrangementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/FinancingArrangementsTables" xlink:href="clh-20190331.xsd#FinancingArrangementsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssets" xlink:href="clh-20190331.xsd#GoodwillAndOtherIntangibleAssets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsAmortizableOtherIntangibleAssetsDetails" xlink:href="clh-20190331.xsd#GoodwillAndOtherIntangibleAssetsAmortizableOtherIntangibleAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsExpectedFutureAmortizationDetails" xlink:href="clh-20190331.xsd#GoodwillAndOtherIntangibleAssetsExpectedFutureAmortizationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:href="clh-20190331.xsd#GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsRollforwardOfGoodwillDetails" xlink:href="clh-20190331.xsd#GoodwillAndOtherIntangibleAssetsRollforwardOfGoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsTables" xlink:href="clh-20190331.xsd#GoodwillAndOtherIntangibleAssetsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformation" xlink:href="clh-20190331.xsd#GuarantorAndNonGuarantorSubsidiariesFinancialInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationCondensedConsolidatingBalanceSheetsDetails" xlink:href="clh-20190331.xsd#GuarantorAndNonGuarantorSubsidiariesFinancialInformationCondensedConsolidatingBalanceSheetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationCondensedConsolidatingStatementsOfCashFlowsDetails" xlink:href="clh-20190331.xsd#GuarantorAndNonGuarantorSubsidiariesFinancialInformationCondensedConsolidatingStatementsOfCashFlowsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationConsolidatingStatementOfOperationsDetails" xlink:href="clh-20190331.xsd#GuarantorAndNonGuarantorSubsidiariesFinancialInformationConsolidatingStatementOfOperationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationNarrativeDetails" xlink:href="clh-20190331.xsd#GuarantorAndNonGuarantorSubsidiariesFinancialInformationNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationTables" xlink:href="clh-20190331.xsd#GuarantorAndNonGuarantorSubsidiariesFinancialInformationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/IncomeTaxes" xlink:href="clh-20190331.xsd#IncomeTaxes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/IncomeTaxesDetails" xlink:href="clh-20190331.xsd#IncomeTaxesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/InventoriesAndSupplies" xlink:href="clh-20190331.xsd#InventoriesAndSupplies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/InventoriesAndSuppliesDetails" xlink:href="clh-20190331.xsd#InventoriesAndSuppliesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/InventoriesAndSuppliesTables" xlink:href="clh-20190331.xsd#InventoriesAndSuppliesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/Leases" xlink:href="clh-20190331.xsd#Leases" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/LeasesLeaseExpenseDetails" xlink:href="clh-20190331.xsd#LeasesLeaseExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/LeasesLeasesOtherInformationDetails" xlink:href="clh-20190331.xsd#LeasesLeasesOtherInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/LeasesScheduleOfFutureLeasePaymentsDetails" xlink:href="clh-20190331.xsd#LeasesScheduleOfFutureLeasePaymentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/LeasesSummaryOfFutureMinimumPaymentsUnderOperatingLeasesDetails" xlink:href="clh-20190331.xsd#LeasesSummaryOfFutureMinimumPaymentsUnderOperatingLeasesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/LeasesSupplementalCashFlowInformationDetails" xlink:href="clh-20190331.xsd#LeasesSupplementalCashFlowInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/LeasesSupplementalFinanceLeaseBalanceSheetInformationDetails" xlink:href="clh-20190331.xsd#LeasesSupplementalFinanceLeaseBalanceSheetInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/LeasesTables" xlink:href="clh-20190331.xsd#LeasesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/PropertyPlantAndEquipment" xlink:href="clh-20190331.xsd#PropertyPlantAndEquipment" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/PropertyPlantAndEquipmentNarrativeDetails" xlink:href="clh-20190331.xsd#PropertyPlantAndEquipmentNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/PropertyPlantAndEquipmentScheduleOfPropertyPlantAndEquipmentDetails" xlink:href="clh-20190331.xsd#PropertyPlantAndEquipmentScheduleOfPropertyPlantAndEquipmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/PropertyPlantAndEquipmentTables" xlink:href="clh-20190331.xsd#PropertyPlantAndEquipmentTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RemedialLiabilities" xlink:href="clh-20190331.xsd#RemedialLiabilities" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RemedialLiabilitiesDetails" xlink:href="clh-20190331.xsd#RemedialLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RemedialLiabilitiesTables" xlink:href="clh-20190331.xsd#RemedialLiabilitiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/Revenues" xlink:href="clh-20190331.xsd#Revenues" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RevenuesContractBalancesDetails" xlink:href="clh-20190331.xsd#RevenuesContractBalancesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RevenuesDisaggregationOfRevenueDetails" xlink:href="clh-20190331.xsd#RevenuesDisaggregationOfRevenueDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RevenuesNarrativeDetails" xlink:href="clh-20190331.xsd#RevenuesNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/RevenuesTables" xlink:href="clh-20190331.xsd#RevenuesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReporting" xlink:href="clh-20190331.xsd#SegmentReporting" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingAdjustedEbitdaInformationDetails" xlink:href="clh-20190331.xsd#SegmentReportingAdjustedEbitdaInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingAssetsByReportableSegmentDetails" xlink:href="clh-20190331.xsd#SegmentReportingAssetsByReportableSegmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingNarrativeDetails" xlink:href="clh-20190331.xsd#SegmentReportingNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingTables" xlink:href="clh-20190331.xsd#SegmentReportingTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingThirdPartyRevenuesToDirectRevenuesDetails" xlink:href="clh-20190331.xsd#SegmentReportingThirdPartyRevenuesToDirectRevenuesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SegmentReportingTotalAssetsByGeographicalAreaDetails" xlink:href="clh-20190331.xsd#SegmentReportingTotalAssetsByGeographicalAreaDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPolicies" xlink:href="clh-20190331.xsd#SignificantAccountingPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesNarrativeDetails" xlink:href="clh-20190331.xsd#SignificantAccountingPoliciesNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/SignificantAccountingPoliciesPolicies" xlink:href="clh-20190331.xsd#SignificantAccountingPoliciesPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensation" xlink:href="clh-20190331.xsd#StockBasedCompensation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensationNarrativeDetails" xlink:href="clh-20190331.xsd#StockBasedCompensationNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensationPerformanceStockAwardsDetails" xlink:href="clh-20190331.xsd#StockBasedCompensationPerformanceStockAwardsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensationRestrictedStockDetails" xlink:href="clh-20190331.xsd#StockBasedCompensationRestrictedStockDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/StockBasedCompensationTables" xlink:href="clh-20190331.xsd#StockBasedCompensationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfCashFlows" xlink:href="clh-20190331.xsd#UnauditedConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfComprehensiveIncomeLoss" xlink:href="clh-20190331.xsd#UnauditedConsolidatedStatementsOfComprehensiveIncomeLoss" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfComprehensiveIncomeLossParenthetical" xlink:href="clh-20190331.xsd#UnauditedConsolidatedStatementsOfComprehensiveIncomeLossParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfOperations" xlink:href="clh-20190331.xsd#UnauditedConsolidatedStatementsOfOperations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfOperationsParenthetical" xlink:href="clh-20190331.xsd#UnauditedConsolidatedStatementsOfOperationsParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfStockholdersEquity" xlink:href="clh-20190331.xsd#UnauditedConsolidatedStatementsOfStockholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfStockholdersEquityParenthetical" xlink:href="clh-20190331.xsd#UnauditedConsolidatedStatementsOfStockholdersEquityParenthetical" 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/AccruedExpensesDetails" 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/AccumulatedOtherComprehensiveLossChangesInAccumulatedOtherComprehensiveLossByComponentDetails" 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_81C5EA63D6C490E141AD5531CA8A378A" 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_D9EBE2BE5465FD49D5E15531CA8AD50C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_81C5EA63D6C490E141AD5531CA8A378A" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_D9EBE2BE5465FD49D5E15531CA8AD50C" 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_B4EE1CEF76C50D63CCB15531CA8A5F4B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_D9EBE2BE5465FD49D5E15531CA8AD50C" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_B4EE1CEF76C50D63CCB15531CA8A5F4B" 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_FB84BBB5061F64B8D7F05531CA8AF338_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_B4EE1CEF76C50D63CCB15531CA8A5F4B" xlink:to="loc_us-gaap_EquityComponentDomain_FB84BBB5061F64B8D7F05531CA8AF338_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_FB84BBB5061F64B8D7F05531CA8AF338" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_B4EE1CEF76C50D63CCB15531CA8A5F4B" xlink:to="loc_us-gaap_EquityComponentDomain_FB84BBB5061F64B8D7F05531CA8AF338" 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_2385AFAC0B20AEE6F4A95531CA8ACA28" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_FB84BBB5061F64B8D7F05531CA8AF338" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_2385AFAC0B20AEE6F4A95531CA8ACA28" 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_00E6D16F7234F423C2365531CA8AC9C5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_FB84BBB5061F64B8D7F05531CA8AF338" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_00E6D16F7234F423C2365531CA8AC9C5" 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_305206BEABF872F717AB5531CA8AA715" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_FB84BBB5061F64B8D7F05531CA8AF338" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_305206BEABF872F717AB5531CA8AA715" 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_95ED8117DBAE6692C1775531CA8A909C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_FB84BBB5061F64B8D7F05531CA8AF338" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_95ED8117DBAE6692C1775531CA8A909C" 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_07C570903937BEEF218E5531CA8A4106" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_FB84BBB5061F64B8D7F05531CA8AF338" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_07C570903937BEEF218E5531CA8A4106" 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_6522034A4DC74B599EB15531CA8AE4CF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_81C5EA63D6C490E141AD5531CA8A378A" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6522034A4DC74B599EB15531CA8AE4CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_ED21F60261F5485DDDA55531CA8A8ACC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6522034A4DC74B599EB15531CA8AE4CF" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_ED21F60261F5485DDDA55531CA8A8ACC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax_A53897FEC2B4A35D15CD5531CA8A1921" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6522034A4DC74B599EB15531CA8AE4CF" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax_A53897FEC2B4A35D15CD5531CA8A1921" 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_346C9BCE8C66349AFD0E5531CA8AF77B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6522034A4DC74B599EB15531CA8AE4CF" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_346C9BCE8C66349AFD0E5531CA8AF77B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax_23FBA6F746F4D87F80705531CA8AA14E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6522034A4DC74B599EB15531CA8AE4CF" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax_23FBA6F746F4D87F80705531CA8AA14E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_AC20E12FD06C80942ED15531CA8AEFD6" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6522034A4DC74B599EB15531CA8AE4CF" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_AC20E12FD06C80942ED15531CA8AEFD6" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossReclassifiedOutOfAccumulatedOtherComprehensiveLossDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems" xlink:label="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_D1B1842B51774E0291236E9F301F3236" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_F3A4E443E51A285D29956E9F301D4284" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_D1B1842B51774E0291236E9F301F3236" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_F3A4E443E51A285D29956E9F301D4284" 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_AED8EEE063F5CCB3D5C56E9F301D7045" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_F3A4E443E51A285D29956E9F301D4284" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_AED8EEE063F5CCB3D5C56E9F301D7045" 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_F3DF48E1F08F33CA594A6E9F301D5875_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_AED8EEE063F5CCB3D5C56E9F301D7045" xlink:to="loc_us-gaap_EquityComponentDomain_F3DF48E1F08F33CA594A6E9F301D5875_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_F3DF48E1F08F33CA594A6E9F301D5875" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_AED8EEE063F5CCB3D5C56E9F301D7045" xlink:to="loc_us-gaap_EquityComponentDomain_F3DF48E1F08F33CA594A6E9F301D5875" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossDerivativeQualifyingAsHedgeExcludedComponentIncludingPortionAttributableToNoncontrollingInterestMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDerivativeQualifyingAsHedgeExcludedComponentIncludingPortionAttributableToNoncontrollingInterestMember_28AB51A9644C2CCB888B6E9F301E037C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_F3DF48E1F08F33CA594A6E9F301D5875" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDerivativeQualifyingAsHedgeExcludedComponentIncludingPortionAttributableToNoncontrollingInterestMember_28AB51A9644C2CCB888B6E9F301E037C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_41A9EA086B7A77F25B406E9F301E6D46" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_F3A4E443E51A285D29956E9F301D4284" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_41A9EA086B7A77F25B406E9F301E6D46" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_C6864194C654B31F008C6E9F301E1A48_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_41A9EA086B7A77F25B406E9F301E6D46" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_C6864194C654B31F008C6E9F301E1A48_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_C6864194C654B31F008C6E9F301E1A48" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_41A9EA086B7A77F25B406E9F301E6D46" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_C6864194C654B31F008C6E9F301E1A48" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_FC64BE7C8225C66978C86E9F301F5030" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_C6864194C654B31F008C6E9F301E1A48" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_FC64BE7C8225C66978C86E9F301F5030" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_DDB4E51EB9B6396CBA326E9F3020B306" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_D1B1842B51774E0291236E9F301F3236" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_DDB4E51EB9B6396CBA326E9F3020B306" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_B62FED5A0CAE7215BA816E9F3020248A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems_D1B1842B51774E0291236E9F301F3236" xlink:to="loc_us-gaap_ProfitLoss_B62FED5A0CAE7215BA816E9F3020248A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/AccumulatedOtherComprehensiveLossTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BasisOfPresentation" 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/BusinessCombinations2018AcquisitionsDetails" 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_D0ACC745BA81D539B3A7553B351CFD3D" 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_5DC1C80DCAC1180D6F08553B351B4ED2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC745BA81D539B3A7553B351CFD3D" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_5DC1C80DCAC1180D6F08553B351B4ED2" 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_9385CF7DE691DD57D5BD553B351B8DD9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_5DC1C80DCAC1180D6F08553B351B4ED2" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_9385CF7DE691DD57D5BD553B351B8DD9" 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_89500CDA7F12D1EA4E88553B351BDA2C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9385CF7DE691DD57D5BD553B351B8DD9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_89500CDA7F12D1EA4E88553B351BDA2C_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_89500CDA7F12D1EA4E88553B351BDA2C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9385CF7DE691DD57D5BD553B351B8DD9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_89500CDA7F12D1EA4E88553B351BDA2C" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_AcquiredCompanyIncludedinSafetyKleenandEnvironmentalServicesSegmentsMember" xlink:label="loc_clh_AcquiredCompanyIncludedinSafetyKleenandEnvironmentalServicesSegmentsMember_9F7E113872FF0FBC1001553B351C0EEC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_89500CDA7F12D1EA4E88553B351BDA2C" xlink:to="loc_clh_AcquiredCompanyIncludedinSafetyKleenandEnvironmentalServicesSegmentsMember_9F7E113872FF0FBC1001553B351C0EEC" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_VeoliaDivisionMember" xlink:label="loc_clh_VeoliaDivisionMember_7C7D28A86EF39F43B074553B351C5C63" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_89500CDA7F12D1EA4E88553B351BDA2C" xlink:to="loc_clh_VeoliaDivisionMember_7C7D28A86EF39F43B074553B351C5C63" 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_1ED8A4D0D61692AA8DF5553B351C13A4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC745BA81D539B3A7553B351CFD3D" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_1ED8A4D0D61692AA8DF5553B351C13A4" 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_D6CBD707321FB63624C2553B351D5C7C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC745BA81D539B3A7553B351CFD3D" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_D6CBD707321FB63624C2553B351D5C7C" 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_8AC4A8E50AD21DE98D70553B351DB719" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC745BA81D539B3A7553B351CFD3D" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_8AC4A8E50AD21DE98D70553B351DB719" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BusinessCombinations2019AcquisitionDetails" 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_B407C42F3EF701D95467422608BB351C" 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_322295FDE7FE6829D080422608B12824" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B407C42F3EF701D95467422608BB351C" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_322295FDE7FE6829D080422608B12824" 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_5B2ED18DB2A1B3D73C84422608B226B9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_322295FDE7FE6829D080422608B12824" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_5B2ED18DB2A1B3D73C84422608B226B9" 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_4A8A5E768020D7B84F20422608B52E86_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5B2ED18DB2A1B3D73C84422608B226B9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4A8A5E768020D7B84F20422608B52E86_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_4A8A5E768020D7B84F20422608B52E86" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5B2ED18DB2A1B3D73C84422608B226B9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4A8A5E768020D7B84F20422608B52E86" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_PrivateHeldCompanyMember" xlink:label="loc_clh_PrivateHeldCompanyMember_061AB1902B8587DFBDBF422642B2B184" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4A8A5E768020D7B84F20422608B52E86" xlink:to="loc_clh_PrivateHeldCompanyMember_061AB1902B8587DFBDBF422642B2B184" 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_135D4984354A29573F774226C8E9AB3E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B407C42F3EF701D95467422608BB351C" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_135D4984354A29573F774226C8E9AB3E" 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_E5E608AB09733B0372AB4226C90336F3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B407C42F3EF701D95467422608BB351C" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_E5E608AB09733B0372AB4226C90336F3" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/BusinessCombinationsAssetsAcquiredAndLiabilitiesAssumedDetails" 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_522C070AEB1C3D80EBF0E015BCF16327" 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_6BC1DC1F5C1DB57B6701E015BCF0F780" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6BC1DC1F5C1DB57B6701E015BCF0F780" 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_A42D03A64918D9BD246BE015BCF0D5E9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_6BC1DC1F5C1DB57B6701E015BCF0F780" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_A42D03A64918D9BD246BE015BCF0D5E9" 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_D88C2546C82AC25F1B3FE015BCF16730_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_A42D03A64918D9BD246BE015BCF0D5E9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D88C2546C82AC25F1B3FE015BCF16730_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_D88C2546C82AC25F1B3FE015BCF16730" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_A42D03A64918D9BD246BE015BCF0D5E9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D88C2546C82AC25F1B3FE015BCF16730" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_VeoliaDivisionMember" xlink:label="loc_clh_VeoliaDivisionMember_C3BA119A285E894F0501E015BCF10381" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D88C2546C82AC25F1B3FE015BCF16730" xlink:to="loc_clh_VeoliaDivisionMember_C3BA119A285E894F0501E015BCF10381" 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_3B6E2F9A32ABAE967F26E015BCF13375" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_3B6E2F9A32ABAE967F26E015BCF13375" 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_6D5C0D8C44297A5EA870E015BCF2041E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_6D5C0D8C44297A5EA870E015BCF2041E" 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_36A808CC03CB5924B7C7E015BCF20503" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_36A808CC03CB5924B7C7E015BCF20503" 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_24B5293D706C5F0F1287E015BCF2FFE0" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_24B5293D706C5F0F1287E015BCF2FFE0" 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_2D16FD8ED608A869CE0FE015BCF31E41" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_2D16FD8ED608A869CE0FE015BCF31E41" 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_61B5B47D57D930B003DCE015BCF3A9C7" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_61B5B47D57D930B003DCE015BCF3A9C7" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesClosureandPostClosureLiabilities" xlink:label="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesClosureandPostClosureLiabilities_86B1D54547FC204BA775E015BCF34F59" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentLiabilitiesClosureandPostClosureLiabilities_86B1D54547FC204BA775E015BCF34F59" 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_048D6D8BC7D9EBFA1FCBE015BCF4057C" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_048D6D8BC7D9EBFA1FCBE015BCF4057C" 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_6D9849A2F3C9D3140362E015BCF402B4" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_Goodwill_6D9849A2F3C9D3140362E015BCF402B4" 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_FA2D6B22E284862A237FE015BCF4A7DC" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_522C070AEB1C3D80EBF0E015BCF16327" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_FA2D6B22E284862A237FE015BCF4A7DC" 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/ClosureAndPostClosureLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:href="clh-20190331.xsd#clh_ClosureAndPostClosureLiabilitiesLineItems" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesLineItems_99D460D019AF553BA86D38C5B70AF7C2" xlink:type="locator" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ClosureAndPostClosureLiabilitiesTable" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesTable_FF63E57E51A45D8D84CD76A5C7DDD103" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesLineItems_99D460D019AF553BA86D38C5B70AF7C2" xlink:to="loc_clh_ClosureAndPostClosureLiabilitiesTable_FF63E57E51A45D8D84CD76A5C7DDD103" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ClosureAndPostClosureLiabilitiesAxis" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesAxis_64C37870304B52B9B9B388A989CF71AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesTable_FF63E57E51A45D8D84CD76A5C7DDD103" xlink:to="loc_clh_ClosureAndPostClosureLiabilitiesAxis_64C37870304B52B9B9B388A989CF71AC" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ClosureAndPostClosureLiabilitiesDomain" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesDomain_566EA1BCFAA997AC54113D55BF7A2147_311BB24B425E582FA75BEA1D866A27C0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesAxis_64C37870304B52B9B9B388A989CF71AC" xlink:to="loc_clh_ClosureAndPostClosureLiabilitiesDomain_566EA1BCFAA997AC54113D55BF7A2147_311BB24B425E582FA75BEA1D866A27C0" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ClosureAndPostClosureLiabilitiesDomain" xlink:label="loc_clh_ClosureAndPostClosureLiabilitiesDomain_642B897F464D5714B0F7CC2E72F614AF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesAxis_64C37870304B52B9B9B388A989CF71AC" xlink:to="loc_clh_ClosureAndPostClosureLiabilitiesDomain_642B897F464D5714B0F7CC2E72F614AF" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_LandfillRetirementLiabilityMember" xlink:label="loc_clh_LandfillRetirementLiabilityMember_9835D3770993559A97A261E174EA4247" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesDomain_642B897F464D5714B0F7CC2E72F614AF" xlink:to="loc_clh_LandfillRetirementLiabilityMember_9835D3770993559A97A261E174EA4247" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_NonLandfillRetirementLiabilityMember" xlink:label="loc_clh_NonLandfillRetirementLiabilityMember_E8ECF1E55A955D7BA205D0F53C014B87" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesDomain_642B897F464D5714B0F7CC2E72F614AF" xlink:to="loc_clh_NonLandfillRetirementLiabilityMember_E8ECF1E55A955D7BA205D0F53C014B87" 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_131C3998D2905A39892407013C703281" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesLineItems_99D460D019AF553BA86D38C5B70AF7C2" xlink:to="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_131C3998D2905A39892407013C703281" 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_DB0C568ED6235F2F809EEDF69BAAA1AA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_131C3998D2905A39892407013C703281" xlink:to="loc_us-gaap_AssetRetirementObligation_DB0C568ED6235F2F809EEDF69BAAA1AA" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_AssetRetirementObligationLiabilitiesAssumedFromBusinessAcquisitionsOriginallyReported" xlink:label="loc_clh_AssetRetirementObligationLiabilitiesAssumedFromBusinessAcquisitionsOriginallyReported_123C3ADD0BEA5FCCA4AEAED1B95B24E6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_131C3998D2905A39892407013C703281" xlink:to="loc_clh_AssetRetirementObligationLiabilitiesAssumedFromBusinessAcquisitionsOriginallyReported_123C3ADD0BEA5FCCA4AEAED1B95B24E6" 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_0A9D0B066BA85F4BBA223B71DAF96998" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_131C3998D2905A39892407013C703281" xlink:to="loc_us-gaap_AssetRetirementObligationLiabilitiesIncurred_0A9D0B066BA85F4BBA223B71DAF96998" 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_614C7CEA6F1554F9B1DE4F1F5C865B12" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_131C3998D2905A39892407013C703281" xlink:to="loc_us-gaap_AssetRetirementObligationAccretionExpense_614C7CEA6F1554F9B1DE4F1F5C865B12" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_AssetRetirementObligationChangesRecordedInStatementOfIncome" xlink:label="loc_clh_AssetRetirementObligationChangesRecordedInStatementOfIncome_F32F3466FF0951D9BFEE9DE91842B591" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_131C3998D2905A39892407013C703281" xlink:to="loc_clh_AssetRetirementObligationChangesRecordedInStatementOfIncome_F32F3466FF0951D9BFEE9DE91842B591" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_AssetRetirementObligationChangesRecordedinBalanceSheet" xlink:label="loc_clh_AssetRetirementObligationChangesRecordedinBalanceSheet_788B9D783BD55298824526B74763A8DF" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_131C3998D2905A39892407013C703281" xlink:to="loc_clh_AssetRetirementObligationChangesRecordedinBalanceSheet_788B9D783BD55298824526B74763A8DF" 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_64B1658285AE567BA1E2C4C64EA605A7" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_131C3998D2905A39892407013C703281" xlink:to="loc_us-gaap_AssetRetirementObligationLiabilitiesSettled_64B1658285AE567BA1E2C4C64EA605A7" 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_8A16AC73404554508CBFD423214C538E" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward_131C3998D2905A39892407013C703281" xlink:to="loc_us-gaap_AssetRetirementObligationForeignCurrencyTranslationGainLoss_8A16AC73404554508CBFD423214C538E" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_AssetRetirementObligationsDiscountRate" xlink:label="loc_clh_AssetRetirementObligationsDiscountRate_82938D0C5334550D9196632C947E3908" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ClosureAndPostClosureLiabilitiesLineItems_99D460D019AF553BA86D38C5B70AF7C2" xlink:to="loc_clh_AssetRetirementObligationsDiscountRate_82938D0C5334550D9196632C947E3908" 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/CommitmentsAndContingenciesDetails" xlink:type="extended">
    <link:loc xlink:href="clh-20190331.xsd#clh_ContingenciesLineItems" xlink:label="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:type="locator" />
    <link:loc xlink:href="clh-20190331.xsd#clh_EnvironmentalContingenciesTable" xlink:label="loc_clh_EnvironmentalContingenciesTable_1FE13AA6A17CBFBFDABE45B1F19D0DB3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_EnvironmentalContingenciesTable_1FE13AA6A17CBFBFDABE45B1F19D0DB3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ContingenciesByNatureOfContingencyAxis" xlink:label="loc_clh_ContingenciesByNatureOfContingencyAxis_0BEF00E0B1F6570D554945B1F19DF906" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_clh_EnvironmentalContingenciesTable_1FE13AA6A17CBFBFDABE45B1F19D0DB3" xlink:to="loc_clh_ContingenciesByNatureOfContingencyAxis_0BEF00E0B1F6570D554945B1F19DF906" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_76BD17EFE4F34156B03545B1F1A3229E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_0BEF00E0B1F6570D554945B1F19DF906" xlink:to="loc_clh_ContingencyNatureDomain_76BD17EFE4F34156B03545B1F1A3229E_default" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ContingencyNatureDomain" xlink:label="loc_clh_ContingencyNatureDomain_76BD17EFE4F34156B03545B1F1A3229E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_clh_ContingenciesByNatureOfContingencyAxis_0BEF00E0B1F6570D554945B1F19DF906" xlink:to="loc_clh_ContingencyNatureDomain_76BD17EFE4F34156B03545B1F1A3229E" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_LegalAndAdministrativeProceedingsMember" xlink:label="loc_clh_LegalAndAdministrativeProceedingsMember_8B52FDEE8AB8B79CF01A45B1F1A3A1E8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingencyNatureDomain_76BD17EFE4F34156B03545B1F1A3229E" xlink:to="loc_clh_LegalAndAdministrativeProceedingsMember_8B52FDEE8AB8B79CF01A45B1F1A3A1E8" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_VilleMercierMember" xlink:label="loc_clh_VilleMercierMember_808434B6315166EECF9F45B1F1A3CCE4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LegalAndAdministrativeProceedingsMember_8B52FDEE8AB8B79CF01A45B1F1A3A1E8" xlink:to="loc_clh_VilleMercierMember_808434B6315166EECF9F45B1F1A3CCE4" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SuperfundProceedingsMember" xlink:label="loc_clh_SuperfundProceedingsMember_66E2940364390F356C1645B1F1A44E77" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingencyNatureDomain_76BD17EFE4F34156B03545B1F1A3229E" xlink:to="loc_clh_SuperfundProceedingsMember_66E2940364390F356C1645B1F1A44E77" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_CertainOtherThirdPartySitesMember" xlink:label="loc_clh_CertainOtherThirdPartySitesMember_66ADF1E45F437AE76B7445B1F1A452B1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsMember_66E2940364390F356C1645B1F1A44E77" xlink:to="loc_clh_CertainOtherThirdPartySitesMember_66ADF1E45F437AE76B7445B1F1A452B1" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_KleenPerformanceProductsMember" xlink:label="loc_clh_KleenPerformanceProductsMember_9ADB9BCC06FBBFD5397F45B1F1A45BE2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_SuperfundProceedingsMember_66E2940364390F356C1645B1F1A44E77" xlink:to="loc_clh_KleenPerformanceProductsMember_9ADB9BCC06FBBFD5397F45B1F1A45BE2" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_FederalAndStateEnforcementActionsMember" xlink:label="loc_clh_FederalAndStateEnforcementActionsMember_B480EB8696384B70D38145B1F1A4BD73" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingencyNatureDomain_76BD17EFE4F34156B03545B1F1A3229E" xlink:to="loc_clh_FederalAndStateEnforcementActionsMember_B480EB8696384B70D38145B1F1A4BD73" 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_7319E599CAEBC99E49FF45B1F1A4F4DE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_clh_EnvironmentalContingenciesTable_1FE13AA6A17CBFBFDABE45B1F19D0DB3" xlink:to="loc_srt_RangeAxis_7319E599CAEBC99E49FF45B1F1A4F4DE" 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_677E01F95B10EBAB1CA645B1F1A59466_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_7319E599CAEBC99E49FF45B1F1A4F4DE" xlink:to="loc_srt_RangeMember_677E01F95B10EBAB1CA645B1F1A59466_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_677E01F95B10EBAB1CA645B1F1A59466" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_7319E599CAEBC99E49FF45B1F1A4F4DE" xlink:to="loc_srt_RangeMember_677E01F95B10EBAB1CA645B1F1A59466" 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_A4C93FA016D4F9BB143A45B1F1A61EBA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_677E01F95B10EBAB1CA645B1F1A59466" xlink:to="loc_srt_MinimumMember_A4C93FA016D4F9BB143A45B1F1A61EBA" 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_8EB34D8E4FD731BA5FDD45B1F1A61A34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_8EB34D8E4FD731BA5FDD45B1F1A61A34" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability" xlink:label="loc_clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability_9F5588D9FCECD365109545B1F1A6FEC5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability_9F5588D9FCECD365109545B1F1A6FEC5" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid" xlink:label="loc_clh_NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid_2D49876687FFE853372645B1F1A70BA5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid_2D49876687FFE853372645B1F1A70BA5" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings" xlink:label="loc_clh_NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings_FE341A2DF74131A164C445B1F1A75882" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings_FE341A2DF74131A164C445B1F1A75882" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_LossContingencyGeneralDamagesSoughtValue" xlink:label="loc_clh_LossContingencyGeneralDamagesSoughtValue_B2B1C00BBECE956E2BF845B1F1A74F1B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_LossContingencyGeneralDamagesSoughtValue_B2B1C00BBECE956E2BF845B1F1A74F1B" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_LossContingencyPunitiveDamagesSoughtValue" xlink:label="loc_clh_LossContingencyPunitiveDamagesSoughtValue_2E231877C1B2C033274045B1F1A78860" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_LossContingencyPunitiveDamagesSoughtValue_2E231877C1B2C033274045B1F1A78860" 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_79CDCF3B50F06DD9164E45B1F1A73071" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_79CDCF3B50F06DD9164E45B1F1A73071" 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_9F4A9E60180152F480C645B1F1A78BD9" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_us-gaap_LossContingencyClaimsSettledAndDismissedNumber_9F4A9E60180152F480C645B1F1A78BD9" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SiteContingencyNumberOfSites" xlink:label="loc_clh_SiteContingencyNumberOfSites_E4194AFF82ED4F8E434945B1F1A8C174" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_SiteContingencyNumberOfSites_E4194AFF82ED4F8E434945B1F1A8C174" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SiteContingencyNumberOfSitesOwnedByEntity" xlink:label="loc_clh_SiteContingencyNumberOfSitesOwnedByEntity_F982EDA368194E1A6B5845B1F1A8145D" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_SiteContingencyNumberOfSitesOwnedByEntity_F982EDA368194E1A6B5845B1F1A8145D" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SiteContingencyNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyNumberOfSitesOwnedByThirdParty_B32FB7927FF3A23D724045B1F1A87D0A" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_SiteContingencyNumberOfSitesOwnedByThirdParty_B32FB7927FF3A23D724045B1F1A87D0A" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty_EDC81349F88AAF76C37645B1F1A8EC58" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty_EDC81349F88AAF76C37645B1F1A8EC58" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty_0F3C754834E96A942D7145B1F1A8423C" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty_0F3C754834E96A942D7145B1F1A8423C" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty_9BE6D8E2A0321D5F639A45B1F1A80D85" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty_9BE6D8E2A0321D5F639A45B1F1A80D85" 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_0CEE667245C979C0AB1E45B1F1A8711E" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_0CEE667245C979C0AB1E45B1F1A8711E" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_NumberofSitesPotentialLiabilityExceedsSubstantialQuota" xlink:label="loc_clh_NumberofSitesPotentialLiabilityExceedsSubstantialQuota_D65048F8D0F1E6A0E98D45B1F1A94785" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_NumberofSitesPotentialLiabilityExceedsSubstantialQuota_D65048F8D0F1E6A0E98D45B1F1A94785" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty_C39D0932B55DDDED926445B1F1A99C95" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty_C39D0932B55DDDED926445B1F1A99C95" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty" xlink:label="loc_clh_SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty_C52DBD03CEFF19782C3F45B1F1A98543" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ContingenciesLineItems_136F3C9D19F98BEFE48C45B1F1A621EC" xlink:to="loc_clh_SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty_C52DBD03CEFF19782C3F45B1F1A98543" xlink:type="arc" />
  </link:definitionLink>
  <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/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/EarningsLossPerShareComputationOfBasicAndDilutedEarningsPerShareDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/EarningsLossPerShareNarrativeDetails" 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_2A9559A20B273EAB974B6E9F3058D7E9" 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_919CFE24BB423AAD05586E9F30564213" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_2A9559A20B273EAB974B6E9F3058D7E9" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_919CFE24BB423AAD05586E9F30564213" 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_139166C6DA87CA006D0C6E9F3057D895" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_919CFE24BB423AAD05586E9F30564213" xlink:to="loc_us-gaap_AwardTypeAxis_139166C6DA87CA006D0C6E9F3057D895" 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_090B2FC44D36A7F1A42A6E9F3057BA5F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_139166C6DA87CA006D0C6E9F3057D895" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_090B2FC44D36A7F1A42A6E9F3057BA5F_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_090B2FC44D36A7F1A42A6E9F3057BA5F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_139166C6DA87CA006D0C6E9F3057D895" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_090B2FC44D36A7F1A42A6E9F3057BA5F" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_PerformanceStockAwardsMember" xlink:label="loc_clh_PerformanceStockAwardsMember_AF3A0876237CFA791C306E9F3057FB27" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_090B2FC44D36A7F1A42A6E9F3057BA5F" xlink:to="loc_clh_PerformanceStockAwardsMember_AF3A0876237CFA791C306E9F3057FB27" 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_77C329C9BD069F52F5D66E9F30587828" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_090B2FC44D36A7F1A42A6E9F3057BA5F" xlink:to="loc_us-gaap_RestrictedStockMember_77C329C9BD069F52F5D66E9F30587828" 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_7E7C287BFBCA69CCF2A36E9F30587766" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_2A9559A20B273EAB974B6E9F3058D7E9" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_7E7C287BFBCA69CCF2A36E9F30587766" xlink:type="arc" />
  </link:definitionLink>
  <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_23C08C71D0ACE4E6B1B7456BDA5BDEDB" 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_00AA48398AE08C02B21F456BDA55220B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_DebtInstrumentTable_00AA48398AE08C02B21F456BDA55220B" 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_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_5DACDD8E405D38B0C95D456BDA5670E1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_00AA48398AE08C02B21F456BDA55220B" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_5DACDD8E405D38B0C95D456BDA5670E1" 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_46B36245FE40207BC37C456BDA56CE75_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_5DACDD8E405D38B0C95D456BDA5670E1" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_46B36245FE40207BC37C456BDA56CE75_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_46B36245FE40207BC37C456BDA56CE75" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_5DACDD8E405D38B0C95D456BDA5670E1" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_46B36245FE40207BC37C456BDA56CE75" 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_A4BAB27B932E7ECC5422456BDA5673C9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_46B36245FE40207BC37C456BDA56CE75" xlink:to="loc_us-gaap_InterestRateSwapMember_A4BAB27B932E7ECC5422456BDA5673C9" 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_5A325D7015A29D2C74C0456BDA575A61" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_00AA48398AE08C02B21F456BDA55220B" xlink:to="loc_us-gaap_VariableRateAxis_5A325D7015A29D2C74C0456BDA575A61" 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_3809AA0000C9DC52DFD1456BDA574675_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_5A325D7015A29D2C74C0456BDA575A61" xlink:to="loc_us-gaap_VariableRateDomain_3809AA0000C9DC52DFD1456BDA574675_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_3809AA0000C9DC52DFD1456BDA574675" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_5A325D7015A29D2C74C0456BDA575A61" xlink:to="loc_us-gaap_VariableRateDomain_3809AA0000C9DC52DFD1456BDA574675" 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_6081C189D0FAE9483531456BDA57C7B2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_3809AA0000C9DC52DFD1456BDA574675" xlink:to="loc_us-gaap_EurodollarMember_6081C189D0FAE9483531456BDA57C7B2" xlink:type="arc" />
    <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_AC2DFC80064EDE84D26C456BDA57C40F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_00AA48398AE08C02B21F456BDA55220B" xlink:to="loc_us-gaap_CreditFacilityAxis_AC2DFC80064EDE84D26C456BDA57C40F" 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_866A9D870BB96659E70D456BDA58A271_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_AC2DFC80064EDE84D26C456BDA57C40F" xlink:to="loc_us-gaap_CreditFacilityDomain_866A9D870BB96659E70D456BDA58A271_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_866A9D870BB96659E70D456BDA58A271" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_AC2DFC80064EDE84D26C456BDA57C40F" xlink:to="loc_us-gaap_CreditFacilityDomain_866A9D870BB96659E70D456BDA58A271" 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_F3F32279681A26E4A798456BDA588062" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_866A9D870BB96659E70D456BDA58A271" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_F3F32279681A26E4A798456BDA588062" 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_21FFA1F48BADB0A048A7456BDA583367" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_00AA48398AE08C02B21F456BDA55220B" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_21FFA1F48BADB0A048A7456BDA583367" 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_E3C01AA6D8C35A5723CB456BDA5810D3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_21FFA1F48BADB0A048A7456BDA583367" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_E3C01AA6D8C35A5723CB456BDA5810D3_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_E3C01AA6D8C35A5723CB456BDA5810D3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_21FFA1F48BADB0A048A7456BDA583367" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_E3C01AA6D8C35A5723CB456BDA5810D3" 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_9F782DDA31E149217110456BDA594FC9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_E3C01AA6D8C35A5723CB456BDA5810D3" xlink:to="loc_us-gaap_SecuredDebtMember_9F782DDA31E149217110456BDA594FC9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnsecuredDebtMember" xlink:label="loc_us-gaap_UnsecuredDebtMember_F47205953523FF5E9A97456BDA59A410" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_E3C01AA6D8C35A5723CB456BDA5810D3" xlink:to="loc_us-gaap_UnsecuredDebtMember_F47205953523FF5E9A97456BDA59A410" 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_64EA22139773E9784FDE456BDA594184" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_E3C01AA6D8C35A5723CB456BDA5810D3" xlink:to="loc_us-gaap_LineOfCreditMember_64EA22139773E9784FDE456BDA594184" 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_C9FB2FA18ABF7CAB7805456BDA5AF367" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_00AA48398AE08C02B21F456BDA55220B" xlink:to="loc_us-gaap_DebtInstrumentAxis_C9FB2FA18ABF7CAB7805456BDA5AF367" 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_3A424D8136ABF7D2A37D456BDA5AC8C1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_C9FB2FA18ABF7CAB7805456BDA5AF367" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3A424D8136ABF7D2A37D456BDA5AC8C1_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_3A424D8136ABF7D2A37D456BDA5AC8C1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_C9FB2FA18ABF7CAB7805456BDA5AF367" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3A424D8136ABF7D2A37D456BDA5AC8C1" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_TermLoanAgreementMember" xlink:label="loc_clh_TermLoanAgreementMember_E83FB8F6BC7E0B84ACA5456BDA5A5D91" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3A424D8136ABF7D2A37D456BDA5AC8C1" xlink:to="loc_clh_TermLoanAgreementMember_E83FB8F6BC7E0B84ACA5456BDA5A5D91" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_UnsecuredSeniorNotes2021Member" xlink:label="loc_clh_UnsecuredSeniorNotes2021Member_4B09574951624B9A89AE456BDA5B9C87" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3A424D8136ABF7D2A37D456BDA5AC8C1" xlink:to="loc_clh_UnsecuredSeniorNotes2021Member_4B09574951624B9A89AE456BDA5B9C87" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_TermLoanswithInterestRateSwapAgreementsMember" xlink:label="loc_clh_TermLoanswithInterestRateSwapAgreementsMember_49472B8C9A65D99FB8B1456BDA5B10EB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3A424D8136ABF7D2A37D456BDA5AC8C1" xlink:to="loc_clh_TermLoanswithInterestRateSwapAgreementsMember_49472B8C9A65D99FB8B1456BDA5B10EB" 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_B55900A4D0CCAE6E955B456BDA5BD911" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_B55900A4D0CCAE6E955B456BDA5BD911" 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_16F7CCABFC6DF98ED23E456BDA5C603D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_LongTermDebtFairValue_16F7CCABFC6DF98ED23E456BDA5C603D" 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_A107715C95319AF5118F456BDA5C95DE" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_A107715C95319AF5118F456BDA5C95DE" 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_8F79CC3F32337BE254CA456BDA5C491E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_8F79CC3F32337BE254CA456BDA5C491E" 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_259157637C8E10F501FD456BDA5DF88E" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_259157637C8E10F501FD456BDA5DF88E" 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_3498D1376791AB5040FB456BDA5D97CD" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_LongTermDebt_3498D1376791AB5040FB456BDA5D97CD" 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_CFE96A65ED30DC42473B456BDA5D200A" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_invest_DerivativeNotionalAmount_CFE96A65ED30DC42473B456BDA5D200A" 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_890DD42534B5BFD9D8AA456BDA5D9ED6" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_890DD42534B5BFD9D8AA456BDA5D9ED6" 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_0E5E8D5991B552A563D7456BDA5D8C63" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_0E5E8D5991B552A563D7456BDA5D8C63" 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_5C46193B310E19F90E86456BDA5D80A9" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_23C08C71D0ACE4E6B1B7456BDA5BDEDB" xlink:to="loc_us-gaap_DerivativeLiabilities_5C46193B310E19F90E86456BDA5D80A9" 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_419B705D65AC250310CF456BDA6A1979" 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_74415B634AB1A494F8A6456BDA6805DF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_419B705D65AC250310CF456BDA6A1979" xlink:to="loc_us-gaap_DebtInstrumentTable_74415B634AB1A494F8A6456BDA6805DF" 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_619352B8358B0B92D865456BDA68C7EB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_74415B634AB1A494F8A6456BDA6805DF" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_619352B8358B0B92D865456BDA68C7EB" 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_3BD0F86E8EBEFFEC60BC456BDA6821BC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_619352B8358B0B92D865456BDA68C7EB" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3BD0F86E8EBEFFEC60BC456BDA6821BC_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_3BD0F86E8EBEFFEC60BC456BDA6821BC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_619352B8358B0B92D865456BDA68C7EB" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3BD0F86E8EBEFFEC60BC456BDA6821BC" 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_67E9E8426473D39CA18C456BDA698768" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_3BD0F86E8EBEFFEC60BC456BDA6821BC" xlink:to="loc_us-gaap_SecuredDebtMember_67E9E8426473D39CA18C456BDA698768" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnsecuredDebtMember" xlink:label="loc_us-gaap_UnsecuredDebtMember_39FAE9970C7B9B5C6165456BDA69578D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_3BD0F86E8EBEFFEC60BC456BDA6821BC" xlink:to="loc_us-gaap_UnsecuredDebtMember_39FAE9970C7B9B5C6165456BDA69578D" 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_E4B86C2DEC908923A25D456BDA69CA53" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_3BD0F86E8EBEFFEC60BC456BDA6821BC" xlink:to="loc_us-gaap_LineOfCreditMember_E4B86C2DEC908923A25D456BDA69CA53" 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_F0C1460F146B92B7C8C3456BDA69CD50" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_74415B634AB1A494F8A6456BDA6805DF" xlink:to="loc_us-gaap_DebtInstrumentAxis_F0C1460F146B92B7C8C3456BDA69CD50" 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_D5768C0EBC83AE0E2279456BDA694E70_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_F0C1460F146B92B7C8C3456BDA69CD50" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_D5768C0EBC83AE0E2279456BDA694E70_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_D5768C0EBC83AE0E2279456BDA694E70" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_F0C1460F146B92B7C8C3456BDA69CD50" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_D5768C0EBC83AE0E2279456BDA694E70" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_TermLoanAgreementMember" xlink:label="loc_clh_TermLoanAgreementMember_2A12BCBC2EFFBE60D0E1456BDA6A88F9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_D5768C0EBC83AE0E2279456BDA694E70" xlink:to="loc_clh_TermLoanAgreementMember_2A12BCBC2EFFBE60D0E1456BDA6A88F9" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_UnsecuredSeniorNotes2021Member" xlink:label="loc_clh_UnsecuredSeniorNotes2021Member_2D185AB9BFEC837069D4456BDA6AB52F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_D5768C0EBC83AE0E2279456BDA694E70" xlink:to="loc_clh_UnsecuredSeniorNotes2021Member_2D185AB9BFEC837069D4456BDA6AB52F" 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_D37E30CEA6076DCB93A9456BDA6AB840" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_419B705D65AC250310CF456BDA6A1979" xlink:to="loc_us-gaap_LongTermDebtCurrent_D37E30CEA6076DCB93A9456BDA6AB840" 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_18C9810AB09B476D72CC456BDA6B969E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_419B705D65AC250310CF456BDA6A1979" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_18C9810AB09B476D72CC456BDA6B969E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_CB5D95BC1BBC3FEB35AE456BDA6BCC7C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_419B705D65AC250310CF456BDA6A1979" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_CB5D95BC1BBC3FEB35AE456BDA6BCC7C" 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_94EEE1152877F9F58002456BDA6B612A" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_419B705D65AC250310CF456BDA6A1979" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_94EEE1152877F9F58002456BDA6B612A" 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_F7AEE4F55F633D74ABC8456BDA6B7420" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_419B705D65AC250310CF456BDA6A1979" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_F7AEE4F55F633D74ABC8456BDA6B7420" 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/GoodwillAndOtherIntangibleAssetsAmortizableOtherIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="clh-20190331.xsd#clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:label="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_5260393F0A6BE761713C5531CB4F0AD4" xlink:type="locator" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" xlink:label="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_64105A1A10362ACD66065531CB456A95" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_5260393F0A6BE761713C5531CB4F0AD4" xlink:to="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_64105A1A10362ACD66065531CB456A95" 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_597995F1CE1F9159E2485531CB4533D6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_64105A1A10362ACD66065531CB456A95" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_597995F1CE1F9159E2485531CB4533D6" 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_021F5D458B90ABF96EB25531CB45834D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_597995F1CE1F9159E2485531CB4533D6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_021F5D458B90ABF96EB25531CB45834D_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_021F5D458B90ABF96EB25531CB45834D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_597995F1CE1F9159E2485531CB4533D6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_021F5D458B90ABF96EB25531CB45834D" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_PermitsMember" xlink:label="loc_clh_PermitsMember_F1E4F6997B061B0A46AC5531CB45BCC6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_021F5D458B90ABF96EB25531CB45834D" xlink:to="loc_clh_PermitsMember_F1E4F6997B061B0A46AC5531CB45BCC6" 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_D5679C8088EACC3F52735531CB45E256" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_021F5D458B90ABF96EB25531CB45834D" xlink:to="loc_us-gaap_CustomerRelationshipsMember_D5679C8088EACC3F52735531CB45E256" 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_74BFB8415ED7214AF3F65531CB4F1980" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_021F5D458B90ABF96EB25531CB45834D" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_74BFB8415ED7214AF3F65531CB4F1980" 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_CB7ADA423EF56534AEE85531CB4F45AF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable_64105A1A10362ACD66065531CB456A95" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_CB7ADA423EF56534AEE85531CB4F45AF" 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_D47CC091D980929023C55531CB4F6B15_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_CB7ADA423EF56534AEE85531CB4F45AF" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_D47CC091D980929023C55531CB4F6B15_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_D47CC091D980929023C55531CB4F6B15" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_CB7ADA423EF56534AEE85531CB4F45AF" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_D47CC091D980929023C55531CB4F6B15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_686BD0350B8F41399DEA5531CB4FAEA6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_D47CC091D980929023C55531CB4F6B15" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_686BD0350B8F41399DEA5531CB4FAEA6" 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_F5EBE3641CAAE468F8665531CB4FF0FF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_5260393F0A6BE761713C5531CB4F0AD4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_F5EBE3641CAAE468F8665531CB4FF0FF" 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_A17377CF675FE490F9215531CB4F0CB4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_5260393F0A6BE761713C5531CB4F0AD4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_A17377CF675FE490F9215531CB4F0CB4" 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_5053DDF187F88397B3965531CB4F0A1B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_5260393F0A6BE761713C5531CB4F0AD4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_5053DDF187F88397B3965531CB4F0A1B" 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_1F6D0F764FA0089A9D745531CB4FAA55" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_5260393F0A6BE761713C5531CB4F0AD4" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_1F6D0F764FA0089A9D745531CB4FAA55" 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_8ABE7FEE489688CEF3145531CB4F159D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_5260393F0A6BE761713C5531CB4F0AD4" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_8ABE7FEE489688CEF3145531CB4F159D" 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_12D9D4309CE0F60FD7915531CB4F71AF" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems_5260393F0A6BE761713C5531CB4F0AD4" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_12D9D4309CE0F60FD7915531CB4F71AF" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsExpectedFutureAmortizationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GoodwillAndOtherIntangibleAssetsRollforwardOfGoodwillDetails" 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_EE46F2FBD87E52DC9E56BAD38A62D362" 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_947AC57B8F035C859DA391C67CF48E30" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_EE46F2FBD87E52DC9E56BAD38A62D362" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_947AC57B8F035C859DA391C67CF48E30" 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_A4C505C24CDD521C85F658A246970913" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_947AC57B8F035C859DA391C67CF48E30" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_A4C505C24CDD521C85F658A246970913" 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_443F931CFF6794DA91F79B10F092545D_DA36E2E18EFF5A46B9A922F1A141AF60" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_A4C505C24CDD521C85F658A246970913" xlink:to="loc_us-gaap_SegmentDomain_443F931CFF6794DA91F79B10F092545D_DA36E2E18EFF5A46B9A922F1A141AF60" 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_1097E0C3380B598994D01999D68BFBB2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_A4C505C24CDD521C85F658A246970913" xlink:to="loc_us-gaap_SegmentDomain_1097E0C3380B598994D01999D68BFBB2" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_EnvironmentalServicesMember" xlink:label="loc_clh_EnvironmentalServicesMember_B3005AF15DD65A25A87D45AA2F726D04" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1097E0C3380B598994D01999D68BFBB2" xlink:to="loc_clh_EnvironmentalServicesMember_B3005AF15DD65A25A87D45AA2F726D04" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_9898B0427C3E5ADD9227A65DDAF179C9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1097E0C3380B598994D01999D68BFBB2" xlink:to="loc_clh_SafetyKleenMember_9898B0427C3E5ADD9227A65DDAF179C9" 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_AA55C3A410325C0089EFD81FDF35B545" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_EE46F2FBD87E52DC9E56BAD38A62D362" xlink:to="loc_us-gaap_GoodwillRollForward_AA55C3A410325C0089EFD81FDF35B545" 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_15C0B44588FD52DAB8F3BFC1231D1040" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_AA55C3A410325C0089EFD81FDF35B545" xlink:to="loc_us-gaap_Goodwill_15C0B44588FD52DAB8F3BFC1231D1040" 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_6EB7D8103FDB5F83999DB91D1B886931" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_AA55C3A410325C0089EFD81FDF35B545" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_6EB7D8103FDB5F83999DB91D1B886931" 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_1155DC0C3F45524D8470166463A9157E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_AA55C3A410325C0089EFD81FDF35B545" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_1155DC0C3F45524D8470166463A9157E" 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_E20D16A515D95C13AD325AC75C7847FE" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_AA55C3A410325C0089EFD81FDF35B545" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_E20D16A515D95C13AD325AC75C7847FE" 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/GuarantorAndNonGuarantorSubsidiariesFinancialInformation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationCondensedConsolidatingBalanceSheetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_srt_CondensedFinancialStatementsCaptionsLineItems_731BFB9C36B23BB0646165DB08B1E462" 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_9C598DF47CF913A56B6C65DB08AD0D93" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_731BFB9C36B23BB0646165DB08B1E462" xlink:to="loc_srt_ScheduleOfCondensedFinancialStatementsTable_9C598DF47CF913A56B6C65DB08AD0D93" 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_09A60E518806150BAB8F65DB08AE0E1B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_9C598DF47CF913A56B6C65DB08AD0D93" xlink:to="loc_srt_ConsolidationItemsAxis_09A60E518806150BAB8F65DB08AE0E1B" 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_FF09804541FF60C878B465DB08AECB97_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_09A60E518806150BAB8F65DB08AE0E1B" xlink:to="loc_srt_ConsolidationItemsDomain_FF09804541FF60C878B465DB08AECB97_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_FF09804541FF60C878B465DB08AECB97" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_09A60E518806150BAB8F65DB08AE0E1B" xlink:to="loc_srt_ConsolidationItemsDomain_FF09804541FF60C878B465DB08AECB97" 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_6DAECD87B3D3D92F0BD865DB08AEBA1C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_FF09804541FF60C878B465DB08AECB97" xlink:to="loc_srt_ReportableLegalEntitiesMember_6DAECD87B3D3D92F0BD865DB08AEBA1C" 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_2AD84C348FC6AF14BCCB65DB08AE0071" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_FF09804541FF60C878B465DB08AECB97" xlink:to="loc_srt_ConsolidationEliminationsMember_2AD84C348FC6AF14BCCB65DB08AE0071" 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_914D307DA363F98E40D665DB08AFF4FF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_9C598DF47CF913A56B6C65DB08AD0D93" xlink:to="loc_srt_ConsolidatedEntitiesAxis_914D307DA363F98E40D665DB08AFF4FF" 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_8550BBE3B075B9219FB565DB08AF24D7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_914D307DA363F98E40D665DB08AFF4FF" xlink:to="loc_srt_ConsolidatedEntitiesDomain_8550BBE3B075B9219FB565DB08AF24D7_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_8550BBE3B075B9219FB565DB08AF24D7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_914D307DA363F98E40D665DB08AFF4FF" xlink:to="loc_srt_ConsolidatedEntitiesDomain_8550BBE3B075B9219FB565DB08AF24D7" 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_BEE29E14BFB2DD5366E165DB08AFFE38" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_8550BBE3B075B9219FB565DB08AF24D7" xlink:to="loc_srt_ParentCompanyMember_BEE29E14BFB2DD5366E165DB08AFFE38" 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_D42917A6540A08225FDF65DB08B08310" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_8550BBE3B075B9219FB565DB08AF24D7" xlink:to="loc_srt_GuarantorSubsidiariesMember_D42917A6540A08225FDF65DB08B08310" 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_48947056B2D5B770F5B165DB08B02C1F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_8550BBE3B075B9219FB565DB08AF24D7" xlink:to="loc_srt_NonGuarantorSubsidiariesMember_48947056B2D5B770F5B165DB08B02C1F" 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_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_731BFB9C36B23BB0646165DB08B1E462" xlink:to="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_AC0DCDEAF67C6D6314DD65DB08B21088" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_AC0DCDEAF67C6D6314DD65DB08B21088" 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_8AC0C7EFA3DAE52CEDA865DB08B2EC51" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_8AC0C7EFA3DAE52CEDA865DB08B2EC51" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ReceivablesFromAffiliatesSubsidiariesAndHoldingCompanies" xlink:label="loc_clh_ReceivablesFromAffiliatesSubsidiariesAndHoldingCompanies_992FF233223B640A125B65DB08B741BE" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_clh_ReceivablesFromAffiliatesSubsidiariesAndHoldingCompanies_992FF233223B640A125B65DB08B741BE" 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_4E853E392320FE36649865DB08B72281" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_4E853E392320FE36649865DB08B72281" 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_074A9F48907481BB920665DB08B8D125" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_OtherAssetsCurrent_074A9F48907481BB920665DB08B8D125" 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_07F2885A7ECDC663F12D65DB08B81DDE" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_07F2885A7ECDC663F12D65DB08B81DDE" 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_D968D85F62DA1580612365DB08B8982E" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures_D968D85F62DA1580612365DB08B8982E" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_DebtReceivableFromAffiliatesSubsidiariesAndHoldingCompanies" xlink:label="loc_clh_DebtReceivableFromAffiliatesSubsidiariesAndHoldingCompanies_E1C316D3A5BC3A674BB265DB08B806B4" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_clh_DebtReceivableFromAffiliatesSubsidiariesAndHoldingCompanies_E1C316D3A5BC3A674BB265DB08B806B4" 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_0115A18EEC1140B877E165DB08B88A61" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_0115A18EEC1140B877E165DB08B88A61" 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_83478AC720579E0198A465DB08B89F92" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_Goodwill_83478AC720579E0198A465DB08B89F92" 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_C9A459CD351EB69FB2CC65DB08B903BC" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_C9A459CD351EB69FB2CC65DB08B903BC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAssetsMiscellaneousNoncurrent" xlink:label="loc_us-gaap_OtherAssetsMiscellaneousNoncurrent_0FDF3BF1027C900E74FC65DB08B91BF0" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_OtherAssetsMiscellaneousNoncurrent_0FDF3BF1027C900E74FC65DB08B91BF0" 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_DBB47785BC6E3DE974FC65DB08B917D3" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_B3789BEA80C9B1564D9C65DB08B12A9C" xlink:to="loc_us-gaap_Assets_DBB47785BC6E3DE974FC65DB08B917D3" 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_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_731BFB9C36B23BB0646165DB08B1E462" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" 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_B884DC205548CA1EE51A65DB08B9E752" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_us-gaap_LiabilitiesCurrent_B884DC205548CA1EE51A65DB08B9E752" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_PayablesToAffiliatesSubsidiariesAndHoldingCompanies" xlink:label="loc_clh_PayablesToAffiliatesSubsidiariesAndHoldingCompanies_78FCBAC0D57169972FE265DB08BAE7AF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_clh_PayablesToAffiliatesSubsidiariesAndHoldingCompanies_78FCBAC0D57169972FE265DB08BAE7AF" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ClosurePostClosureAndRemedialLiabilitiesNet" xlink:label="loc_clh_ClosurePostClosureAndRemedialLiabilitiesNet_A525E309A8170FDC982265DB08BADB8F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_clh_ClosurePostClosureAndRemedialLiabilitiesNet_A525E309A8170FDC982265DB08BADB8F" 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_40646180F6EF0568301D65DB08BA0A62" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_40646180F6EF0568301D65DB08BA0A62" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_OperatingandFinanceLeaseLiabilityNoncurrent" xlink:label="loc_clh_OperatingandFinanceLeaseLiabilityNoncurrent_74C64B6CA8F4941EDA7865DB08BAF360" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_clh_OperatingandFinanceLeaseLiabilityNoncurrent_74C64B6CA8F4941EDA7865DB08BAF360" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_DebtPayableToAffiliatesSubsidiariesAndHoldingCompanies" xlink:label="loc_clh_DebtPayableToAffiliatesSubsidiariesAndHoldingCompanies_CE666AB4E098513D65C865DB08BA1ED5" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_clh_DebtPayableToAffiliatesSubsidiariesAndHoldingCompanies_CE666AB4E098513D65C865DB08BA1ED5" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent" xlink:label="loc_clh_UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent_66A77387D3FD1C4DA75C65DB08BB0E2A" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_clh_UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent_66A77387D3FD1C4DA75C65DB08BB0E2A" 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_C9D76E789E3B0801AC6D65DB08BB85EA" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_us-gaap_Liabilities_C9D76E789E3B0801AC6D65DB08BB85EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_C9B15D46CE07E2890C5465DB08BB4AA1" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_C9B15D46CE07E2890C5465DB08BB4AA1" 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_557F846C77F0CBD5F23665DB08BB3B64" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_51A4733CBCA8B86E85B465DB08B9DFF3" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_557F846C77F0CBD5F23665DB08BB3B64" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationCondensedConsolidatingStatementsOfCashFlowsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_srt_CondensedFinancialStatementsCaptionsLineItems_2740E747C80F217F94E36E9F2E8114F9" 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_667AF0914F8F868698346E9F2E7EC2F3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_2740E747C80F217F94E36E9F2E8114F9" xlink:to="loc_srt_ScheduleOfCondensedFinancialStatementsTable_667AF0914F8F868698346E9F2E7EC2F3" 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_ConsolidatedEntitiesAxis" xlink:label="loc_srt_ConsolidatedEntitiesAxis_6D986C27C3D70A2B23E36E9F2E7F9E2D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_667AF0914F8F868698346E9F2E7EC2F3" xlink:to="loc_srt_ConsolidatedEntitiesAxis_6D986C27C3D70A2B23E36E9F2E7F9E2D" 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_A7FC3C2CF798595181666E9F2E7F0E8F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_6D986C27C3D70A2B23E36E9F2E7F9E2D" xlink:to="loc_srt_ConsolidatedEntitiesDomain_A7FC3C2CF798595181666E9F2E7F0E8F_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_A7FC3C2CF798595181666E9F2E7F0E8F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_6D986C27C3D70A2B23E36E9F2E7F9E2D" xlink:to="loc_srt_ConsolidatedEntitiesDomain_A7FC3C2CF798595181666E9F2E7F0E8F" 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_E33228BE155A07C0B11F6E9F2E7FF086" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_A7FC3C2CF798595181666E9F2E7F0E8F" xlink:to="loc_srt_ParentCompanyMember_E33228BE155A07C0B11F6E9F2E7FF086" 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_4A22A4F0F31CB2A7C0576E9F2E807C0D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_A7FC3C2CF798595181666E9F2E7F0E8F" xlink:to="loc_srt_GuarantorSubsidiariesMember_4A22A4F0F31CB2A7C0576E9F2E807C0D" 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_AA9D349E8419BF547E806E9F2E80E569" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_A7FC3C2CF798595181666E9F2E7F0E8F" xlink:to="loc_srt_NonGuarantorSubsidiariesMember_AA9D349E8419BF547E806E9F2E80E569" 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_C7BE59BBABD078758D916E9F2E8072B2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_667AF0914F8F868698346E9F2E7EC2F3" xlink:to="loc_srt_ConsolidationItemsAxis_C7BE59BBABD078758D916E9F2E8072B2" 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_BD4B4830995F63678B756E9F2E804A09_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_C7BE59BBABD078758D916E9F2E8072B2" xlink:to="loc_srt_ConsolidationItemsDomain_BD4B4830995F63678B756E9F2E804A09_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_BD4B4830995F63678B756E9F2E804A09" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_C7BE59BBABD078758D916E9F2E8072B2" xlink:to="loc_srt_ConsolidationItemsDomain_BD4B4830995F63678B756E9F2E804A09" 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_4D40712DA8997CEF10E66E9F2E80786C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_BD4B4830995F63678B756E9F2E804A09" xlink:to="loc_srt_ReportableLegalEntitiesMember_4D40712DA8997CEF10E66E9F2E80786C" 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_BC482195FB2869AB6C396E9F2E81B009" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_BD4B4830995F63678B756E9F2E804A09" xlink:to="loc_srt_ConsolidationEliminationsMember_BC482195FB2869AB6C396E9F2E81B009" 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_6E9F2D0465498149A2DC6E9F2E813714" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_2740E747C80F217F94E36E9F2E8114F9" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_6E9F2D0465498149A2DC6E9F2E813714" 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_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_2740E747C80F217F94E36E9F2E8114F9" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" 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_2174A812DE47C9E084B56E9F2E823EBF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_2174A812DE47C9E084B56E9F2E823EBF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleOfProductiveAssets" xlink:label="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_4B317FFDE6FC852F685E6E9F2E87E9B1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_4B317FFDE6FC852F685E6E9F2E87E9B1" 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_10AD2A4C6B2EA62A47156E9F2E872582" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_10AD2A4C6B2EA62A47156E9F2E872582" 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_54B9B9D51BAD165F07106E9F2E87E177" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_us-gaap_PaymentsToAcquireIntangibleAssets_54B9B9D51BAD165F07106E9F2E87E177" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_417A8F96D51533F813E16E9F2E884D60" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_417A8F96D51533F813E16E9F2E884D60" 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_8D88F496218A72E116C96E9F2E88671C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_8D88F496218A72E116C96E9F2E88671C" 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_988A3AECD40B009864336E9F2E88FD9E" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_us-gaap_ProceedsFromSaleOfLongtermInvestments_988A3AECD40B009864336E9F2E88FD9E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecurities" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_58315B41A3EA383FE2DE6E9F2E88B643" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_58315B41A3EA383FE2DE6E9F2E88B643" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_IntercompanyInvesting" xlink:label="loc_clh_IntercompanyInvesting_3A252B70E16483B72AA66E9F2E88EB97" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_clh_IntercompanyInvesting_3A252B70E16483B72AA66E9F2E88EB97" 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_736C6333A0440826C6E06E9F2E8971D4" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0004C5B63E1852FBD2DC6E9F2E8151A4" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_736C6333A0440826C6E06E9F2E8971D4" 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_004C06F6D6DF0A8F91C66E9F2E892622" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_2740E747C80F217F94E36E9F2E8114F9" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_004C06F6D6DF0A8F91C66E9F2E892622" 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_FAD48A9AADF83B2F01456E9F2E8989B8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_004C06F6D6DF0A8F91C66E9F2E892622" xlink:to="loc_us-gaap_IncreaseDecreaseInOutstandingChecksFinancingActivities_FAD48A9AADF83B2F01456E9F2E8989B8" 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_8C23C55DCF839681D6B66E9F2E89FFE7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_004C06F6D6DF0A8F91C66E9F2E892622" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_8C23C55DCF839681D6B66E9F2E89FFE7" 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_856A7350A18F60AEA2686E9F2E895888" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_004C06F6D6DF0A8F91C66E9F2E892622" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_856A7350A18F60AEA2686E9F2E895888" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FinanceLeasePrincipalPayments" xlink:label="loc_us-gaap_FinanceLeasePrincipalPayments_3EE3C2920A570A0E833A6E9F2E8A3249" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_004C06F6D6DF0A8F91C66E9F2E892622" xlink:to="loc_us-gaap_FinanceLeasePrincipalPayments_3EE3C2920A570A0E833A6E9F2E8A3249" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RepaymentsOfUnsecuredDebt" xlink:label="loc_us-gaap_RepaymentsOfUnsecuredDebt_2BCBEE57318AD23B9EF76E9F2E8A3C28" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_004C06F6D6DF0A8F91C66E9F2E892622" xlink:to="loc_us-gaap_RepaymentsOfUnsecuredDebt_2BCBEE57318AD23B9EF76E9F2E8A3C28" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_IntercompanyFinancing" xlink:label="loc_clh_IntercompanyFinancing_0315591935EB99C997AA6E9F2E8A7B1F" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_004C06F6D6DF0A8F91C66E9F2E892622" xlink:to="loc_clh_IntercompanyFinancing_0315591935EB99C997AA6E9F2E8A7B1F" 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_E611CD9B142160CB1CF16E9F2E8A2EFE" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_004C06F6D6DF0A8F91C66E9F2E892622" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_E611CD9B142160CB1CF16E9F2E8A2EFE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_2C41AD26F1CD27FF58406E9F2E8A52B0" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_2740E747C80F217F94E36E9F2E8114F9" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_2C41AD26F1CD27FF58406E9F2E8A52B0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_576A53435CC21A931D316E9F2E8ABBDE" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_2740E747C80F217F94E36E9F2E8114F9" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_576A53435CC21A931D316E9F2E8ABBDE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_2EA6E7B5753A3CE330726E9F2E8B221C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_2740E747C80F217F94E36E9F2E8114F9" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_2EA6E7B5753A3CE330726E9F2E8B221C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationConsolidatingStatementOfOperationsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" 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_6EB5D550131D3399334665DB67EFC5B0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_srt_ScheduleOfCondensedFinancialStatementsTable_6EB5D550131D3399334665DB67EFC5B0" 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_E2D3593E9382E037934065DB67EFBAE7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_6EB5D550131D3399334665DB67EFC5B0" xlink:to="loc_srt_ProductOrServiceAxis_E2D3593E9382E037934065DB67EFBAE7" 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_8A2A6DCD5B2D5040095C65DB67F0621E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_E2D3593E9382E037934065DB67EFBAE7" xlink:to="loc_srt_ProductsAndServicesDomain_8A2A6DCD5B2D5040095C65DB67F0621E_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_8A2A6DCD5B2D5040095C65DB67F0621E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_E2D3593E9382E037934065DB67EFBAE7" xlink:to="loc_srt_ProductsAndServicesDomain_8A2A6DCD5B2D5040095C65DB67F0621E" 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_D6CDE96F01188EEEB3B765DB67F0DBD7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8A2A6DCD5B2D5040095C65DB67F0621E" xlink:to="loc_us-gaap_ServiceMember_D6CDE96F01188EEEB3B765DB67F0DBD7" 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_6309921345A6C2BF26FD65DB67F07807" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8A2A6DCD5B2D5040095C65DB67F0621E" xlink:to="loc_us-gaap_ProductMember_6309921345A6C2BF26FD65DB67F07807" 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_191A7577C1100934260365DB67F14710" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_6EB5D550131D3399334665DB67EFC5B0" xlink:to="loc_srt_ConsolidationItemsAxis_191A7577C1100934260365DB67F14710" 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_3298A25F43947C3123A565DB67F1295C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_191A7577C1100934260365DB67F14710" xlink:to="loc_srt_ConsolidationItemsDomain_3298A25F43947C3123A565DB67F1295C_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_3298A25F43947C3123A565DB67F1295C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_191A7577C1100934260365DB67F14710" xlink:to="loc_srt_ConsolidationItemsDomain_3298A25F43947C3123A565DB67F1295C" 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_F1DE7ABA3C56071C418165DB67F1D545" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_3298A25F43947C3123A565DB67F1295C" xlink:to="loc_srt_ReportableLegalEntitiesMember_F1DE7ABA3C56071C418165DB67F1D545" 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_D3E17C21744FD9D5E7C665DB67F14D95" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_3298A25F43947C3123A565DB67F1295C" xlink:to="loc_srt_ConsolidationEliminationsMember_D3E17C21744FD9D5E7C665DB67F14D95" 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_C937290544006501648065DB67F2504F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ScheduleOfCondensedFinancialStatementsTable_6EB5D550131D3399334665DB67EFC5B0" xlink:to="loc_srt_ConsolidatedEntitiesAxis_C937290544006501648065DB67F2504F" 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_3860E50F68CB53AC581265DB67F24559_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_C937290544006501648065DB67F2504F" xlink:to="loc_srt_ConsolidatedEntitiesDomain_3860E50F68CB53AC581265DB67F24559_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_3860E50F68CB53AC581265DB67F24559" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_C937290544006501648065DB67F2504F" xlink:to="loc_srt_ConsolidatedEntitiesDomain_3860E50F68CB53AC581265DB67F24559" 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_0087A844021F63F9154965DB67F2E918" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_3860E50F68CB53AC581265DB67F24559" xlink:to="loc_srt_ParentCompanyMember_0087A844021F63F9154965DB67F2E918" 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_D8AB2D915623EB52A93D65DB67F28188" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_3860E50F68CB53AC581265DB67F24559" xlink:to="loc_srt_GuarantorSubsidiariesMember_D8AB2D915623EB52A93D65DB67F28188" 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_57F350E48638BF0A4FDB65DB67F2C1C6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_3860E50F68CB53AC581265DB67F24559" xlink:to="loc_srt_NonGuarantorSubsidiariesMember_57F350E48638BF0A4FDB65DB67F2C1C6" 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_809EBA310D2D909021BB65DB67F3BA68" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_RevenuesAbstract_809EBA310D2D909021BB65DB67F3BA68" 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_D5999FC8527E972A66F465DB67F3B5D9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_809EBA310D2D909021BB65DB67F3BA68" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_D5999FC8527E972A66F465DB67F3B5D9" 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_552F12491830C9D8815065DB67F3B5BB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_CostOfRevenueAbstract_552F12491830C9D8815065DB67F3B5BB" 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_489FCFA83FE45F85BC1365DB67F4A0AD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_552F12491830C9D8815065DB67F3B5BB" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_489FCFA83FE45F85BC1365DB67F4A0AD" 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_DDA8CA9568B111C68C4965DB67F421D5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_DDA8CA9568B111C68C4965DB67F421D5" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_AccretionOfEnvironmentalLiabilities" xlink:label="loc_clh_AccretionOfEnvironmentalLiabilities_6DDE00283647B957C49365DB67F4A532" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_clh_AccretionOfEnvironmentalLiabilities_6DDE00283647B957C49365DB67F4A532" 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_894C89ED2C812220518265DB67F4D16D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_894C89ED2C812220518265DB67F4D16D" 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_351BAE01BD57CA76587565DB67F48A2F" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_OperatingIncomeLoss_351BAE01BD57CA76587565DB67F48A2F" 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_1C5B6ADD4D0721CBDDE565DB67F4F292" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_1C5B6ADD4D0721CBDDE565DB67F4F292" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_E37F03484CEFD82800EC65DB67F57F12" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_E37F03484CEFD82800EC65DB67F57F12" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_IncomeLossFromAffiliatesSubsidiariesAndHoldingCompany" xlink:label="loc_clh_IncomeLossFromAffiliatesSubsidiariesAndHoldingCompany_25E31372EB35FD9BDC4165DB67F5ED8C" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_clh_IncomeLossFromAffiliatesSubsidiariesAndHoldingCompany_25E31372EB35FD9BDC4165DB67F5ED8C" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_NetInterestIncomeFromAffiliatesSubsidiariesAndHoldingCompany" xlink:label="loc_clh_NetInterestIncomeFromAffiliatesSubsidiariesAndHoldingCompany_CBB94040DAD2378F4C3465DB67F592D4" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_clh_NetInterestIncomeFromAffiliatesSubsidiariesAndHoldingCompany_CBB94040DAD2378F4C3465DB67F592D4" 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_106E1F23EE39769B7BC865DB67F50530" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_106E1F23EE39769B7BC865DB67F50530" 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_92E5F7DF455E09C8F96965DB67F5AD92" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_92E5F7DF455E09C8F96965DB67F5AD92" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_57145A75E6F78F250DD565DB67F6E97B" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_ProfitLoss_57145A75E6F78F250DD565DB67F6E97B" 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_2968B3DBBFB511A10FCF65DB67F609CB" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_2968B3DBBFB511A10FCF65DB67F609CB" 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_4FBDBC9C77DF663F524765DB67F6337D" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CondensedFinancialStatementsCaptionsLineItems_C36D5EC692551D8E8EAB65DB67F3B204" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_4FBDBC9C77DF663F524765DB67F6337D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/GuarantorAndNonGuarantorSubsidiariesFinancialInformationTables" 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/IncomeTaxesDetails" 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/Leases" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/LeasesLeaseExpenseDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/LeasesLeasesOtherInformationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/LeasesScheduleOfFutureLeasePaymentsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/LeasesSummaryOfFutureMinimumPaymentsUnderOperatingLeasesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/LeasesSupplementalCashFlowInformationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/LeasesSupplementalFinanceLeaseBalanceSheetInformationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/LeasesTables" 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/PropertyPlantAndEquipmentNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/PropertyPlantAndEquipmentScheduleOfPropertyPlantAndEquipmentDetails" 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_9E62F5BDF34A499E5E22553B34EDE270" 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_51C61BCF5FA96E0B0799553B34EABF7D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_9E62F5BDF34A499E5E22553B34EDE270" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_51C61BCF5FA96E0B0799553B34EABF7D" 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_AD3929F102293F79A017553B34EBBB01" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_51C61BCF5FA96E0B0799553B34EABF7D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_AD3929F102293F79A017553B34EBBB01" 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_E90DC0D01B0ED5EE1491553B34EB2893_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_AD3929F102293F79A017553B34EBBB01" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893_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_E90DC0D01B0ED5EE1491553B34EB2893" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_AD3929F102293F79A017553B34EBBB01" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" 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_3F39B94E1AC5878F41E8553B34EB2FCE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" xlink:to="loc_us-gaap_LandMember_3F39B94E1AC5878F41E8553B34EB2FCE" 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_4733AD9BA1C81576552E553B34EC7114" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" xlink:to="loc_us-gaap_AssetRetirementObligationCostsMember_4733AD9BA1C81576552E553B34EC7114" 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_909E101386F1DA14D085553B34ECB723" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" xlink:to="loc_us-gaap_LandfillMember_909E101386F1DA14D085553B34ECB723" 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_A844137E309EEA2E8E87553B34EC321E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_A844137E309EEA2E8E87553B34EC321E" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_CampEquipmentMember" xlink:label="loc_clh_CampEquipmentMember_99164230A66115268722553B34ECD732" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" xlink:to="loc_clh_CampEquipmentMember_99164230A66115268722553B34ECD732" 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_88891A3DE8E8B9D1CDB7553B34EC2BB0" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" xlink:to="loc_us-gaap_VehiclesMember_88891A3DE8E8B9D1CDB7553B34EC2BB0" 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_C36F598347111BFDA85C553B34EC0630" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" xlink:to="loc_us-gaap_EquipmentMember_C36F598347111BFDA85C553B34EC0630" 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_F634C74FF25C02FE3207553B34ED841D" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_F634C74FF25C02FE3207553B34ED841D" 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_A098079B810190F85134553B34EDA89D" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E90DC0D01B0ED5EE1491553B34EB2893" xlink:to="loc_us-gaap_ConstructionInProgressMember_A098079B810190F85134553B34EDA89D" 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_D4D5EFFBA77277502D58553B34ED8C65" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_9E62F5BDF34A499E5E22553B34EDE270" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_D4D5EFFBA77277502D58553B34ED8C65" 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_72B04234EB0B4431C6C6553B34EDA2F6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_9E62F5BDF34A499E5E22553B34EDE270" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_72B04234EB0B4431C6C6553B34EDA2F6" 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_435D182FA1DAC4D3B837553B34EE9B2C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_9E62F5BDF34A499E5E22553B34EDE270" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_435D182FA1DAC4D3B837553B34EE9B2C" 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/RemedialLiabilities" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/RemedialLiabilitiesDetails" 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_277E0D2A40A64A47EE722234A346C813" 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_3615C255B7E9732314892234A345F4F4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SiteContingencyLineItems_277E0D2A40A64A47EE722234A346C813" xlink:to="loc_us-gaap_SiteContingencyTable_3615C255B7E9732314892234A345F4F4" 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_683D67D72E1B05D75BD72234A345EFD5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SiteContingencyTable_3615C255B7E9732314892234A345F4F4" xlink:to="loc_us-gaap_EnvironmentalRemediationSiteAxis_683D67D72E1B05D75BD72234A345EFD5" 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_497DF2957E4D7FD74B532234A345CDB5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteAxis_683D67D72E1B05D75BD72234A345EFD5" xlink:to="loc_us-gaap_EnvironmentalRemediationSiteDomain_497DF2957E4D7FD74B532234A345CDB5_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_497DF2957E4D7FD74B532234A345CDB5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteAxis_683D67D72E1B05D75BD72234A345EFD5" xlink:to="loc_us-gaap_EnvironmentalRemediationSiteDomain_497DF2957E4D7FD74B532234A345CDB5" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_RemedialLiabilitiesForLandfillSitesMember" xlink:label="loc_clh_RemedialLiabilitiesForLandfillSitesMember_074EF089D7B6C71601272234A3462580" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_497DF2957E4D7FD74B532234A345CDB5" xlink:to="loc_clh_RemedialLiabilitiesForLandfillSitesMember_074EF089D7B6C71601272234A3462580" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_RemedialLiabilitiesForInactiveSitesMember" xlink:label="loc_clh_RemedialLiabilitiesForInactiveSitesMember_2BACF984879E541C96D12234A346262D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_497DF2957E4D7FD74B532234A345CDB5" xlink:to="loc_clh_RemedialLiabilitiesForInactiveSitesMember_2BACF984879E541C96D12234A346262D" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember" xlink:label="loc_clh_RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember_A0AA4E33F1643665A7BD2234A3462B30" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_497DF2957E4D7FD74B532234A345CDB5" xlink:to="loc_clh_RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember_A0AA4E33F1643665A7BD2234A3462B30" 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_9D33F1CBB8692F5B2A252234A346A2E6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_277E0D2A40A64A47EE722234A346C813" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_9D33F1CBB8692F5B2A252234A346A2E6" 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_E25C335A63E3FFE161F22234A347D808" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_9D33F1CBB8692F5B2A252234A346A2E6" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingencies_E25C335A63E3FFE161F22234A347D808" 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_F39EC6911DC6B64086732234A34C37B1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_9D33F1CBB8692F5B2A252234A346A2E6" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses_F39EC6911DC6B64086732234A34C37B1" 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_4A830DB5FF6DA5DE2DE52234A34CA0B3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_9D33F1CBB8692F5B2A252234A346A2E6" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForRevisionInEstimates_4A830DB5FF6DA5DE2DE52234A34CA0B3" 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_17DA69633F2F38F8CF102234A34C302E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_9D33F1CBB8692F5B2A252234A346A2E6" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesPayments1_17DA69633F2F38F8CF102234A34C302E" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther" xlink:label="loc_clh_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther_A7D6E740A0E5B9E156082234A34D366A" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccrualForEnvironmentalLossContingenciesRollForward_9D33F1CBB8692F5B2A252234A346A2E6" xlink:to="loc_clh_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther_A7D6E740A0E5B9E156082234A34D366A" 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_36A9E74BF748F0370CC15531CBB3DE44" 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_F2553D4EDD3F338AE0675531CBA93783" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_36A9E74BF748F0370CC15531CBB3DE44" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_F2553D4EDD3F338AE0675531CBA93783" 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_C822EAA93BEF88D8E4505531CBA976D8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_F2553D4EDD3F338AE0675531CBA93783" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_C822EAA93BEF88D8E4505531CBA976D8" 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_1B3A2A74E66699E2E9865531CBA95A1A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_C822EAA93BEF88D8E4505531CBA976D8" xlink:to="loc_us-gaap_SegmentDomain_1B3A2A74E66699E2E9865531CBA95A1A_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_1B3A2A74E66699E2E9865531CBA95A1A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_C822EAA93BEF88D8E4505531CBA976D8" xlink:to="loc_us-gaap_SegmentDomain_1B3A2A74E66699E2E9865531CBA95A1A" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_EnvironmentalServicesMember" xlink:label="loc_clh_EnvironmentalServicesMember_850DADB9CA4D47B5628D5531CBA904F4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1B3A2A74E66699E2E9865531CBA95A1A" xlink:to="loc_clh_EnvironmentalServicesMember_850DADB9CA4D47B5628D5531CBA904F4" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_FFCD57CE0956D58AC19F5531CBB35962" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1B3A2A74E66699E2E9865531CBA95A1A" xlink:to="loc_clh_SafetyKleenMember_FFCD57CE0956D58AC19F5531CBB35962" 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_7CBF89750633944C72565531CBB356FE" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_1B3A2A74E66699E2E9865531CBA95A1A" xlink:to="loc_us-gaap_CorporateMember_7CBF89750633944C72565531CBB356FE" 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_A53B85A8BE2FF247EB4A5531CBB3B6C5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_F2553D4EDD3F338AE0675531CBA93783" xlink:to="loc_srt_ProductOrServiceAxis_A53B85A8BE2FF247EB4A5531CBB3B6C5" 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_9F210E4A06239B4367E95531CBB3D039_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_A53B85A8BE2FF247EB4A5531CBB3B6C5" xlink:to="loc_srt_ProductsAndServicesDomain_9F210E4A06239B4367E95531CBB3D039_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_9F210E4A06239B4367E95531CBB3D039" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_A53B85A8BE2FF247EB4A5531CBB3B6C5" xlink:to="loc_srt_ProductsAndServicesDomain_9F210E4A06239B4367E95531CBB3D039" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_TechnicalServicesMember" xlink:label="loc_clh_TechnicalServicesMember_961097854BB22DE8E1D05531CBB30440" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9F210E4A06239B4367E95531CBB3D039" xlink:to="loc_clh_TechnicalServicesMember_961097854BB22DE8E1D05531CBB30440" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_FieldandEmergencyResponseMember" xlink:label="loc_clh_FieldandEmergencyResponseMember_D7324D9D3D97ABFE69EB5531CBB3BE4F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9F210E4A06239B4367E95531CBB3D039" xlink:to="loc_clh_FieldandEmergencyResponseMember_D7324D9D3D97ABFE69EB5531CBB3BE4F" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_IndustrialServicesMember" xlink:label="loc_clh_IndustrialServicesMember_8EB7C260365218FA5CA95531CBB39412" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9F210E4A06239B4367E95531CBB3D039" xlink:to="loc_clh_IndustrialServicesMember_8EB7C260365218FA5CA95531CBB39412" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_OilGasandLodgingServicesMember" xlink:label="loc_clh_OilGasandLodgingServicesMember_D84BEC34D678841D49E35531CBB36B2B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9F210E4A06239B4367E95531CBB3D039" xlink:to="loc_clh_OilGasandLodgingServicesMember_D84BEC34D678841D49E35531CBB36B2B" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SafetlyKleenEnvironmentalServicesMember" xlink:label="loc_clh_SafetlyKleenEnvironmentalServicesMember_E706D4C0D20953F58FAA5531CBB3E02F" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9F210E4A06239B4367E95531CBB3D039" xlink:to="loc_clh_SafetlyKleenEnvironmentalServicesMember_E706D4C0D20953F58FAA5531CBB3E02F" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SafetyKleenOilMember" xlink:label="loc_clh_SafetyKleenOilMember_DACBF55CCD991C50394D5531CBB3597E" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9F210E4A06239B4367E95531CBB3D039" xlink:to="loc_clh_SafetyKleenOilMember_DACBF55CCD991C50394D5531CBB3597E" 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_1FC240043B21F4C59DE05531CBB382DE" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_F2553D4EDD3F338AE0675531CBA93783" xlink:to="loc_srt_StatementGeographicalAxis_1FC240043B21F4C59DE05531CBB382DE" 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_EBD2801EA4A737F52A405531CBB3BA2C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_1FC240043B21F4C59DE05531CBB382DE" xlink:to="loc_srt_SegmentGeographicalDomain_EBD2801EA4A737F52A405531CBB3BA2C_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_EBD2801EA4A737F52A405531CBB3BA2C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_1FC240043B21F4C59DE05531CBB382DE" xlink:to="loc_srt_SegmentGeographicalDomain_EBD2801EA4A737F52A405531CBB3BA2C" 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_157ACD8C2667D35FAA4D5531CBB3442F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_EBD2801EA4A737F52A405531CBB3BA2C" xlink:to="loc_country_US_157ACD8C2667D35FAA4D5531CBB3442F" 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_94A79E6DEDE53A1EF6DD5531CBB3CB99" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_EBD2801EA4A737F52A405531CBB3BA2C" xlink:to="loc_country_CA_94A79E6DEDE53A1EF6DD5531CBB3CB99" 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_44676396FC4523B821085531CBB358DA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_36A9E74BF748F0370CC15531CBB3DE44" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_44676396FC4523B821085531CBB358DA" 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_2752904DF03C5E45AE4455E6D3477776" 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_E464DE7CDEFD51C1A8FB4EBF7D0B7018" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2752904DF03C5E45AE4455E6D3477776" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_E464DE7CDEFD51C1A8FB4EBF7D0B7018" 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_44FAE4254435539C8F2DD62AF818922B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_E464DE7CDEFD51C1A8FB4EBF7D0B7018" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_44FAE4254435539C8F2DD62AF818922B" 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_269FCF178F01061B6DE43D55C07D1CD7_311BB24B425E582FA75BEA1D866A27C0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_44FAE4254435539C8F2DD62AF818922B" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_269FCF178F01061B6DE43D55C07D1CD7_311BB24B425E582FA75BEA1D866A27C0" 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_81A15B12E13F5616A2F7A09ADE4FB5E0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_44FAE4254435539C8F2DD62AF818922B" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_81A15B12E13F5616A2F7A09ADE4FB5E0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CustomerContractsMember" xlink:label="loc_us-gaap_CustomerContractsMember_9D5D0272438D53C28D547CC5B078341B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_81A15B12E13F5616A2F7A09ADE4FB5E0" xlink:to="loc_us-gaap_CustomerContractsMember_9D5D0272438D53C28D547CC5B078341B" 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_70EB1D4B06BA5FD3A0187DCD93B11DDD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_E464DE7CDEFD51C1A8FB4EBF7D0B7018" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_70EB1D4B06BA5FD3A0187DCD93B11DDD" 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_3544CE324460AFB6F0173D55C07EE75D_311BB24B425E582FA75BEA1D866A27C0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_70EB1D4B06BA5FD3A0187DCD93B11DDD" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3544CE324460AFB6F0173D55C07EE75D_311BB24B425E582FA75BEA1D866A27C0" 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_829EA46FCD7B5A4AA22847F8C1063217" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_70EB1D4B06BA5FD3A0187DCD93B11DDD" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_829EA46FCD7B5A4AA22847F8C1063217" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_VeoliaDivisionMember" xlink:label="loc_clh_VeoliaDivisionMember_0FC090CA31A65C3FBCD6B639831EA413" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_829EA46FCD7B5A4AA22847F8C1063217" xlink:to="loc_clh_VeoliaDivisionMember_0FC090CA31A65C3FBCD6B639831EA413" 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_CF757F955BC2542E8E8728A0A87FAF56" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2752904DF03C5E45AE4455E6D3477776" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_CF757F955BC2542E8E8728A0A87FAF56" 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_D0DB7FE4DBA7506CBEEDC132AD863024" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2752904DF03C5E45AE4455E6D3477776" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_D0DB7FE4DBA7506CBEEDC132AD863024" 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/SegmentReporting" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingAdjustedEbitdaInformationDetails" 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_BAE92D2C438C8B619E104209DB52516F" 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_CC48A37CA0B67E6088404209DB51AE28" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_BAE92D2C438C8B619E104209DB52516F" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_CC48A37CA0B67E6088404209DB51AE28" 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_EF978C0B3225BA5254204209DB5187C5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_CC48A37CA0B67E6088404209DB51AE28" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_EF978C0B3225BA5254204209DB5187C5" 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_5EF24B2AD03EB4DB50C34209DB5167A3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_EF978C0B3225BA5254204209DB5187C5" xlink:to="loc_us-gaap_SegmentDomain_5EF24B2AD03EB4DB50C34209DB5167A3_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_5EF24B2AD03EB4DB50C34209DB5167A3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_EF978C0B3225BA5254204209DB5187C5" xlink:to="loc_us-gaap_SegmentDomain_5EF24B2AD03EB4DB50C34209DB5167A3" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_EnvironmentalServicesMember" xlink:label="loc_clh_EnvironmentalServicesMember_E0D7E02E4555FE23AC684209DB51229D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5EF24B2AD03EB4DB50C34209DB5167A3" xlink:to="loc_clh_EnvironmentalServicesMember_E0D7E02E4555FE23AC684209DB51229D" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_34D05D93C546F227AC3F4209DB52547E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5EF24B2AD03EB4DB50C34209DB5167A3" xlink:to="loc_clh_SafetyKleenMember_34D05D93C546F227AC3F4209DB52547E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CorporateAndOtherMember" xlink:label="loc_us-gaap_CorporateAndOtherMember_8C94A45659C3E9472F2C4209DB52DCBC" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5EF24B2AD03EB4DB50C34209DB5167A3" xlink:to="loc_us-gaap_CorporateAndOtherMember_8C94A45659C3E9472F2C4209DB52DCBC" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet" xlink:label="loc_clh_IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet_B474C91E908BF1A315F54209DB52B4DC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_BAE92D2C438C8B619E104209DB52516F" xlink:to="loc_clh_IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet_B474C91E908BF1A315F54209DB52B4DC" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract" xlink:label="loc_clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract_6CD35EBBDD9C1A3DD39A4209DB53D2F6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_BAE92D2C438C8B619E104209DB52516F" xlink:to="loc_clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract_6CD35EBBDD9C1A3DD39A4209DB53D2F6" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_AccretionOfEnvironmentalLiabilities" xlink:label="loc_clh_AccretionOfEnvironmentalLiabilities_D750D4912F475B3A05A24209DB53D0D8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract_6CD35EBBDD9C1A3DD39A4209DB53D2F6" xlink:to="loc_clh_AccretionOfEnvironmentalLiabilities_D750D4912F475B3A05A24209DB53D0D8" 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_DE9074FAAE95314BC53E4209DB53A3F8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract_6CD35EBBDD9C1A3DD39A4209DB53D2F6" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_DE9074FAAE95314BC53E4209DB53A3F8" 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_26E733F0BC805B7C84A54209DB53B7B0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract_6CD35EBBDD9C1A3DD39A4209DB53D2F6" xlink:to="loc_us-gaap_OperatingIncomeLoss_26E733F0BC805B7C84A54209DB53B7B0" 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_1FB2BF2F34C85CFE83084209DB5438AB" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract_6CD35EBBDD9C1A3DD39A4209DB53D2F6" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_1FB2BF2F34C85CFE83084209DB5438AB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_DC26301039E67C43F4A84209DB5420DC" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract_6CD35EBBDD9C1A3DD39A4209DB53D2F6" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_DC26301039E67C43F4A84209DB5420DC" 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_EC6DFD503C0226B47B9B4209DB541072" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract_6CD35EBBDD9C1A3DD39A4209DB53D2F6" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_EC6DFD503C0226B47B9B4209DB541072" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingAssetsByReportableSegmentDetails" 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_7F7D79AF94970D93A3CB4209DB4B2F02" 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_DD363EEFC2F184942D084209DB48E689" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_7F7D79AF94970D93A3CB4209DB4B2F02" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_DD363EEFC2F184942D084209DB48E689" 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_9950B9B7DC69A5CD1EFC4209DB484A27" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_DD363EEFC2F184942D084209DB48E689" xlink:to="loc_srt_ConsolidationItemsAxis_9950B9B7DC69A5CD1EFC4209DB484A27" 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_A28D0DCB65B8B8C3CAC54209DB48C260_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_9950B9B7DC69A5CD1EFC4209DB484A27" xlink:to="loc_srt_ConsolidationItemsDomain_A28D0DCB65B8B8C3CAC54209DB48C260_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_A28D0DCB65B8B8C3CAC54209DB48C260" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_9950B9B7DC69A5CD1EFC4209DB484A27" xlink:to="loc_srt_ConsolidationItemsDomain_A28D0DCB65B8B8C3CAC54209DB48C260" 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_3FEBB19F22983E2FE63A4209DB486BD3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_A28D0DCB65B8B8C3CAC54209DB48C260" xlink:to="loc_us-gaap_OperatingSegmentsMember_3FEBB19F22983E2FE63A4209DB486BD3" 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_D7948D4DAA730CB013804209DB49F20D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_A28D0DCB65B8B8C3CAC54209DB48C260" xlink:to="loc_us-gaap_CorporateNonSegmentMember_D7948D4DAA730CB013804209DB49F20D" 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_CD2A534ED2875A555D824209DB493D0D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_DD363EEFC2F184942D084209DB48E689" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_CD2A534ED2875A555D824209DB493D0D" 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_7B3C7044011ECE1A94804209DB49F116_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_CD2A534ED2875A555D824209DB493D0D" xlink:to="loc_us-gaap_SegmentDomain_7B3C7044011ECE1A94804209DB49F116_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_7B3C7044011ECE1A94804209DB49F116" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_CD2A534ED2875A555D824209DB493D0D" xlink:to="loc_us-gaap_SegmentDomain_7B3C7044011ECE1A94804209DB49F116" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_EnvironmentalServicesMember" xlink:label="loc_clh_EnvironmentalServicesMember_0BAEBB8A153C2F8B574F4209DB495664" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_7B3C7044011ECE1A94804209DB49F116" xlink:to="loc_clh_EnvironmentalServicesMember_0BAEBB8A153C2F8B574F4209DB495664" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_296FAE059716AFCD47774209DB4A547B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_7B3C7044011ECE1A94804209DB49F116" xlink:to="loc_clh_SafetyKleenMember_296FAE059716AFCD47774209DB4A547B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CorporateAndOtherMember" xlink:label="loc_us-gaap_CorporateAndOtherMember_05B4CD5DD24ABBD3E8A74209DB4A82ED" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_7B3C7044011ECE1A94804209DB49F116" xlink:to="loc_us-gaap_CorporateAndOtherMember_05B4CD5DD24ABBD3E8A74209DB4A82ED" 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_9B6B21D87C9B47B0CC4E4209DB4B7145" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_7F7D79AF94970D93A3CB4209DB4B2F02" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_9B6B21D87C9B47B0CC4E4209DB4B7145" 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_F5736A018E0502DD13B54209DB4BF849" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_7F7D79AF94970D93A3CB4209DB4B2F02" xlink:to="loc_us-gaap_Goodwill_F5736A018E0502DD13B54209DB4BF849" 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_9906D8301DFF03AD3AA64209DB4B8FCB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_7F7D79AF94970D93A3CB4209DB4B2F02" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_9906D8301DFF03AD3AA64209DB4B8FCB" 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_BA41108C9FC48215C7944209DB4B2411" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_7F7D79AF94970D93A3CB4209DB4B2F02" xlink:to="loc_us-gaap_Assets_BA41108C9FC48215C7944209DB4B2411" 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_6A780FE4E0318909AFB24209DB4C5A87" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_7F7D79AF94970D93A3CB4209DB4B2F02" xlink:to="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_6A780FE4E0318909AFB24209DB4C5A87" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingThirdPartyRevenuesToDirectRevenuesDetails" 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_F514E54BF289EA4CAE044209DB5BB101" 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_9D06AA6CDAF6A2E656CD4209DB596521" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F514E54BF289EA4CAE044209DB5BB101" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_9D06AA6CDAF6A2E656CD4209DB596521" 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_197D4132942E23E338184209DB593223" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_9D06AA6CDAF6A2E656CD4209DB596521" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_197D4132942E23E338184209DB593223" 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_AB6349E4CB68EB3CE0CB4209DB599F0B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_197D4132942E23E338184209DB593223" xlink:to="loc_us-gaap_SegmentDomain_AB6349E4CB68EB3CE0CB4209DB599F0B_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_AB6349E4CB68EB3CE0CB4209DB599F0B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_197D4132942E23E338184209DB593223" xlink:to="loc_us-gaap_SegmentDomain_AB6349E4CB68EB3CE0CB4209DB599F0B" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_EnvironmentalServicesMember" xlink:label="loc_clh_EnvironmentalServicesMember_DB7DBF1DD8C7BA9D8EC64209DB5AC84A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_AB6349E4CB68EB3CE0CB4209DB599F0B" xlink:to="loc_clh_EnvironmentalServicesMember_DB7DBF1DD8C7BA9D8EC64209DB5AC84A" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_SafetyKleenMember" xlink:label="loc_clh_SafetyKleenMember_E5E062A24FE53B7066834209DB5ADCB2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_AB6349E4CB68EB3CE0CB4209DB599F0B" xlink:to="loc_clh_SafetyKleenMember_E5E062A24FE53B7066834209DB5ADCB2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CorporateAndOtherMember" xlink:label="loc_us-gaap_CorporateAndOtherMember_206B38AEFC14509AA9664209DB5ADC65" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_AB6349E4CB68EB3CE0CB4209DB599F0B" xlink:to="loc_us-gaap_CorporateAndOtherMember_206B38AEFC14509AA9664209DB5ADC65" 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_5C98DB2D2730C64E48894209DB5A8FC0" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_AB6349E4CB68EB3CE0CB4209DB599F0B" xlink:to="loc_us-gaap_CorporateMember_5C98DB2D2730C64E48894209DB5A8FC0" 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_DFFCAE2A2F43EFDA775C4209DB5AC683" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_9D06AA6CDAF6A2E656CD4209DB596521" xlink:to="loc_srt_ConsolidationItemsAxis_DFFCAE2A2F43EFDA775C4209DB5AC683" 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_7874F6EE81B0BB3B899C4209DB5B53E7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_DFFCAE2A2F43EFDA775C4209DB5AC683" xlink:to="loc_srt_ConsolidationItemsDomain_7874F6EE81B0BB3B899C4209DB5B53E7_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_7874F6EE81B0BB3B899C4209DB5B53E7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_DFFCAE2A2F43EFDA775C4209DB5AC683" xlink:to="loc_srt_ConsolidationItemsDomain_7874F6EE81B0BB3B899C4209DB5B53E7" 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_089C8F8623B8074B0AD9425ACB201344" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_7874F6EE81B0BB3B899C4209DB5B53E7" xlink:to="loc_us-gaap_IntersegmentEliminationMember_089C8F8623B8074B0AD9425ACB201344" 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_00A3D860AC59FEACB2C94209DB5BBA75" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_7874F6EE81B0BB3B899C4209DB5B53E7" xlink:to="loc_us-gaap_CorporateNonSegmentMember_00A3D860AC59FEACB2C94209DB5BBA75" 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_C3C652D2C6974757402A4209DB5BE80A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_7874F6EE81B0BB3B899C4209DB5B53E7" xlink:to="loc_us-gaap_OperatingSegmentsMember_C3C652D2C6974757402A4209DB5BE80A" 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_CED4828A57ED393297244209DB5C02B8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_F514E54BF289EA4CAE044209DB5BB101" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_CED4828A57ED393297244209DB5C02B8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SegmentReportingTotalAssetsByGeographicalAreaDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_16A78167D94AA906FD21E969C46EB399" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_A7B0FA0B293E997C2FC2E969C46C261A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_16A78167D94AA906FD21E969C46EB399" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_A7B0FA0B293E997C2FC2E969C46C261A" 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_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_9A864762CEF8B0A098DAE969C46D3E1E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_A7B0FA0B293E997C2FC2E969C46C261A" xlink:to="loc_srt_StatementGeographicalAxis_9A864762CEF8B0A098DAE969C46D3E1E" 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_2469B2F84080FCD683C1E969C46D59C1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_9A864762CEF8B0A098DAE969C46D3E1E" xlink:to="loc_srt_SegmentGeographicalDomain_2469B2F84080FCD683C1E969C46D59C1_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_2469B2F84080FCD683C1E969C46D59C1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_9A864762CEF8B0A098DAE969C46D3E1E" xlink:to="loc_srt_SegmentGeographicalDomain_2469B2F84080FCD683C1E969C46D59C1" 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_E68D4B6132BC97AA7CD9E969C46D3931" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2469B2F84080FCD683C1E969C46D59C1" xlink:to="loc_country_US_E68D4B6132BC97AA7CD9E969C46D3931" 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_A4B9D289842FED89B86BE969C46EC265" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2469B2F84080FCD683C1E969C46D59C1" xlink:to="loc_country_CA_A4B9D289842FED89B86BE969C46EC265" 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_A46BAB13340E226B38A9E969C46E4A65" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_16A78167D94AA906FD21E969C46EB399" xlink:to="loc_us-gaap_Assets_A46BAB13340E226B38A9E969C46E4A65" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPolicies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/SignificantAccountingPoliciesNarrativeDetails" 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_0AD84B632F989C97EF1B5A154563044F" 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_F4C1830AC9FD24088D9A5A154560FA59" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_0AD84B632F989C97EF1B5A154563044F" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_F4C1830AC9FD24088D9A5A154560FA59" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="clh-20190331.xsd#clh_LeaseTypeAxis" xlink:label="loc_clh_LeaseTypeAxis_9E5F8808FBCC2945CDAC5A1A5346D682" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_F4C1830AC9FD24088D9A5A154560FA59" xlink:to="loc_clh_LeaseTypeAxis_9E5F8808FBCC2945CDAC5A1A5346D682" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_LeaseTypeDomain" xlink:label="loc_clh_LeaseTypeDomain_360506949BAFD91AC91C5A1A5346CEEE_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_clh_LeaseTypeAxis_9E5F8808FBCC2945CDAC5A1A5346D682" xlink:to="loc_clh_LeaseTypeDomain_360506949BAFD91AC91C5A1A5346CEEE_default" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_LeaseTypeDomain" xlink:label="loc_clh_LeaseTypeDomain_360506949BAFD91AC91C5A1A5346CEEE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_clh_LeaseTypeAxis_9E5F8808FBCC2945CDAC5A1A5346D682" xlink:to="loc_clh_LeaseTypeDomain_360506949BAFD91AC91C5A1A5346CEEE" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_RealEstateLeasesMember" xlink:label="loc_clh_RealEstateLeasesMember_CD838FEE15D410F98F3D5A1AE933F671" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LeaseTypeDomain_360506949BAFD91AC91C5A1A5346CEEE" xlink:to="loc_clh_RealEstateLeasesMember_CD838FEE15D410F98F3D5A1AE933F671" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_NonRealEstateLeasesMember" xlink:label="loc_clh_NonRealEstateLeasesMember_4F6607B0CFDBAE11BC4D5A1BA4803720" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LeaseTypeDomain_360506949BAFD91AC91C5A1A5346CEEE" xlink:to="loc_clh_NonRealEstateLeasesMember_4F6607B0CFDBAE11BC4D5A1BA4803720" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_ShortTermLeasesMember" xlink:label="loc_clh_ShortTermLeasesMember_44363C4BDBD247B690E85A1C01A968F0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_clh_LeaseTypeDomain_360506949BAFD91AC91C5A1A5346CEEE" xlink:to="loc_clh_ShortTermLeasesMember_44363C4BDBD247B690E85A1C01A968F0" 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_14BD84B3432C3B7FD0DB5A15EA38EB5B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_F4C1830AC9FD24088D9A5A154560FA59" xlink:to="loc_srt_RangeAxis_14BD84B3432C3B7FD0DB5A15EA38EB5B" 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_DC92891B09F98140E9145A15EBC6BAC9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_14BD84B3432C3B7FD0DB5A15EA38EB5B" xlink:to="loc_srt_RangeMember_DC92891B09F98140E9145A15EBC6BAC9_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_DC92891B09F98140E9145A15EBC6BAC9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_14BD84B3432C3B7FD0DB5A15EA38EB5B" xlink:to="loc_srt_RangeMember_DC92891B09F98140E9145A15EBC6BAC9" 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_6101CA85EC132035BB585A1863F1597A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_DC92891B09F98140E9145A15EBC6BAC9" xlink:to="loc_srt_MinimumMember_6101CA85EC132035BB585A1863F1597A" 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_4FB9599C0336F94D8FA35A188C2AF28D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_DC92891B09F98140E9145A15EBC6BAC9" xlink:to="loc_srt_MaximumMember_4FB9599C0336F94D8FA35A188C2AF28D" 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_549C77F3022EF18460225A154561391A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_F4C1830AC9FD24088D9A5A154560FA59" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_549C77F3022EF18460225A154561391A" 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_FFFF5B9C31E07D2190D25A1545611C2D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_549C77F3022EF18460225A154561391A" xlink:to="loc_us-gaap_EquityComponentDomain_FFFF5B9C31E07D2190D25A1545611C2D_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_FFFF5B9C31E07D2190D25A1545611C2D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_549C77F3022EF18460225A154561391A" xlink:to="loc_us-gaap_EquityComponentDomain_FFFF5B9C31E07D2190D25A1545611C2D" 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_EC3B0B76AE9E7D2657CC5A1545610E20" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_FFFF5B9C31E07D2190D25A1545611C2D" xlink:to="loc_us-gaap_RetainedEarningsMember_EC3B0B76AE9E7D2657CC5A1545610E20" 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_3BF4590AEB0B076B9B8B5A1545623C78" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_F4C1830AC9FD24088D9A5A154560FA59" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_3BF4590AEB0B076B9B8B5A1545623C78" 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_74949F7928D2BCAEC4885A1545629761_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_3BF4590AEB0B076B9B8B5A1545623C78" xlink:to="loc_us-gaap_TypeOfAdoptionMember_74949F7928D2BCAEC4885A1545629761_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_74949F7928D2BCAEC4885A1545629761" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_3BF4590AEB0B076B9B8B5A1545623C78" xlink:to="loc_us-gaap_TypeOfAdoptionMember_74949F7928D2BCAEC4885A1545629761" 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_831CD8E8C5684740A1A85A1545623435" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_74949F7928D2BCAEC4885A1545629761" xlink:to="loc_us-gaap_AccountingStandardsUpdate201602Member_831CD8E8C5684740A1A85A1545623435" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseTermOfContract" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_0FBAA788B782C55417B85A15CC16D047" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_0AD84B632F989C97EF1B5A154563044F" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_0FBAA788B782C55417B85A15CC16D047" 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_404ACD88E76E822D9CAD5A1545631553" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_0AD84B632F989C97EF1B5A154563044F" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_404ACD88E76E822D9CAD5A1545631553" 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_5971C0F40612B3F7F0AF5A15456307F8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_0AD84B632F989C97EF1B5A154563044F" xlink:to="loc_us-gaap_OperatingLeaseLiability_5971C0F40612B3F7F0AF5A15456307F8" 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_29E37D9768E5F133D11A5A154563D9AF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_0AD84B632F989C97EF1B5A154563044F" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_29E37D9768E5F133D11A5A154563D9AF" 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/StockBasedCompensation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockBasedCompensationNarrativeDetails" 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_0921F1D52777CF7FD7FD456BD9C1AE6A" 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_AE680F935C8507112FF5456BD9BF9A2A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_AE680F935C8507112FF5456BD9BF9A2A" 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_B385841C6241035188D4456BD9BF1478" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_AE680F935C8507112FF5456BD9BF9A2A" xlink:to="loc_srt_RangeAxis_B385841C6241035188D4456BD9BF1478" 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_BBA598D6C7994EB6DC3F456BD9C0789D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_B385841C6241035188D4456BD9BF1478" xlink:to="loc_srt_RangeMember_BBA598D6C7994EB6DC3F456BD9C0789D_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_BBA598D6C7994EB6DC3F456BD9C0789D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_B385841C6241035188D4456BD9BF1478" xlink:to="loc_srt_RangeMember_BBA598D6C7994EB6DC3F456BD9C0789D" 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_D43E436ACBC859561E78456BD9C0365C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_BBA598D6C7994EB6DC3F456BD9C0789D" xlink:to="loc_srt_MinimumMember_D43E436ACBC859561E78456BD9C0365C" 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_37B54FC8C06C553BDA50456BD9C0AE0C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_BBA598D6C7994EB6DC3F456BD9C0789D" xlink:to="loc_srt_MaximumMember_37B54FC8C06C553BDA50456BD9C0AE0C" 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_91A433905848CD753E2B456BD9C1C6D4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_AE680F935C8507112FF5456BD9BF9A2A" xlink:to="loc_us-gaap_AwardTypeAxis_91A433905848CD753E2B456BD9C1C6D4" 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_002A63D6DEFE93FBC078456BD9C118B6_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_91A433905848CD753E2B456BD9C1C6D4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_002A63D6DEFE93FBC078456BD9C118B6_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_002A63D6DEFE93FBC078456BD9C118B6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_91A433905848CD753E2B456BD9C1C6D4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_002A63D6DEFE93FBC078456BD9C118B6" 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_C31C28412E083F2947CA456BD9C15C95" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_002A63D6DEFE93FBC078456BD9C118B6" xlink:to="loc_us-gaap_RestrictedStockMember_C31C28412E083F2947CA456BD9C15C95" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_PerformanceStockAwardsMember" xlink:label="loc_clh_PerformanceStockAwardsMember_87D225A94076A34471E7456BD9C1BC72" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_002A63D6DEFE93FBC078456BD9C118B6" xlink:to="loc_clh_PerformanceStockAwardsMember_87D225A94076A34471E7456BD9C1BC72" 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_F2DCD412CD4550897FD1456BD9C213FF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_F2DCD412CD4550897FD1456BD9C213FF" 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_57C62D59406D973AE751456BD9C25C47" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_57C62D59406D973AE751456BD9C25C47" 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_3CFEE62D094BC48B70F7456BD9C2F691" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_3CFEE62D094BC48B70F7456BD9C2F691" 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_BDA50C1F939A1CF43599456BD9C2B2A0" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_BDA50C1F939A1CF43599456BD9C2B2A0" 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_47370E2BBFB3D5772309456BD9C29FF7" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_47370E2BBFB3D5772309456BD9C29FF7" 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_F27CE19E5CF74DCBC005456BD9C3112B" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_F27CE19E5CF74DCBC005456BD9C3112B" 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_39E62AC145130D80B0BF45AE62BDF8CF" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_39E62AC145130D80B0BF45AE62BDF8CF" 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_C37A6174B34DD795C16A456BD9C3238C" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_C37A6174B34DD795C16A456BD9C3238C" 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_C65A5C2E5B6A956EA259456BD9C36272" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_C65A5C2E5B6A956EA259456BD9C36272" 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_3E72F61B9F2CDD95D165456BD9C39771" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0921F1D52777CF7FD7FD456BD9C1AE6A" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_3E72F61B9F2CDD95D165456BD9C39771" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockBasedCompensationPerformanceStockAwardsDetails" 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_78CE8F17AEA358EBA0E0449BDCAD5364" 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_4B0B9D1631F85FA590B322D31F46EEE2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_78CE8F17AEA358EBA0E0449BDCAD5364" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4B0B9D1631F85FA590B322D31F46EEE2" 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_C8ACF266E25658B5B9FA92CE719CC89C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4B0B9D1631F85FA590B322D31F46EEE2" xlink:to="loc_us-gaap_AwardTypeAxis_C8ACF266E25658B5B9FA92CE719CC89C" 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_D4E58D27FED306F3422F9B5793CF036E_DA36E2E18EFF5A46B9A922F1A141AF60" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_C8ACF266E25658B5B9FA92CE719CC89C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D4E58D27FED306F3422F9B5793CF036E_DA36E2E18EFF5A46B9A922F1A141AF60" 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_1327101A2A4958FAB40747537E1A3190" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_C8ACF266E25658B5B9FA92CE719CC89C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1327101A2A4958FAB40747537E1A3190" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_PerformanceStockAwardsMember" xlink:label="loc_clh_PerformanceStockAwardsMember_85C68B0594E656AE875AFDE97F99C412" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1327101A2A4958FAB40747537E1A3190" xlink:to="loc_clh_PerformanceStockAwardsMember_85C68B0594E656AE875AFDE97F99C412" 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_1005610AC83151B6B5DE1B42E65BA505" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_78CE8F17AEA358EBA0E0449BDCAD5364" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_1005610AC83151B6B5DE1B42E65BA505" 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_CCFCD2A26B685A4DA3037872B798F685" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_1005610AC83151B6B5DE1B42E65BA505" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_CCFCD2A26B685A4DA3037872B798F685" 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_D7B2383B34405F6E84E1A4DF3CF878C1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_1005610AC83151B6B5DE1B42E65BA505" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_D7B2383B34405F6E84E1A4DF3CF878C1" 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_9514CCCFCED659318B942B932A2F1ADB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_1005610AC83151B6B5DE1B42E65BA505" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_9514CCCFCED659318B942B932A2F1ADB" 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_B3E65E1B35C95B9D8C62402DB4CF50C8" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_1005610AC83151B6B5DE1B42E65BA505" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_B3E65E1B35C95B9D8C62402DB4CF50C8" 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_EAFBD67B824C54498451D86117007C9C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_78CE8F17AEA358EBA0E0449BDCAD5364" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_EAFBD67B824C54498451D86117007C9C" 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_012F2AFD72795C5290EDCE1FF9FDB7B4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_EAFBD67B824C54498451D86117007C9C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_012F2AFD72795C5290EDCE1FF9FDB7B4" 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_146797911C1757D3A08E14571A2DA2DF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_EAFBD67B824C54498451D86117007C9C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_146797911C1757D3A08E14571A2DA2DF" 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_7BB1375A997D56EF9F08E312F9FC386A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_EAFBD67B824C54498451D86117007C9C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_7BB1375A997D56EF9F08E312F9FC386A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_2F46656562EC532B9A99C4DA26FFF137" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_EAFBD67B824C54498451D86117007C9C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_2F46656562EC532B9A99C4DA26FFF137" 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_263B92EA68BC577489F0214E3F6414B0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_78CE8F17AEA358EBA0E0449BDCAD5364" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_263B92EA68BC577489F0214E3F6414B0" 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_C54EC7DCD1695A31BF35C515CA6599D0" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_78CE8F17AEA358EBA0E0449BDCAD5364" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_C54EC7DCD1695A31BF35C515CA6599D0" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockBasedCompensationRestrictedStockDetails" 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_3756FA0FA3E15DC4A050FE5A4FF2E2C5" 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_C859DBC3E2695A0FA741599A1F26CC84" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3756FA0FA3E15DC4A050FE5A4FF2E2C5" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_C859DBC3E2695A0FA741599A1F26CC84" 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_800E1A87157C5EE0BCCEF2B4F582EB31" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_C859DBC3E2695A0FA741599A1F26CC84" xlink:to="loc_srt_RangeAxis_800E1A87157C5EE0BCCEF2B4F582EB31" 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_50341A7F2016D3B673023D55BDDA3AC8_311BB24B425E582FA75BEA1D866A27C0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_800E1A87157C5EE0BCCEF2B4F582EB31" xlink:to="loc_srt_RangeMember_50341A7F2016D3B673023D55BDDA3AC8_311BB24B425E582FA75BEA1D866A27C0" 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_730E8D84CB3D50A39D79AA76535679BC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_800E1A87157C5EE0BCCEF2B4F582EB31" xlink:to="loc_srt_RangeMember_730E8D84CB3D50A39D79AA76535679BC" 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_BB5B0811EE795323B35F8BFF353B04A0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_730E8D84CB3D50A39D79AA76535679BC" xlink:to="loc_srt_MinimumMember_BB5B0811EE795323B35F8BFF353B04A0" 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_6D3FCE2B977956728D02AABB33138485" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_730E8D84CB3D50A39D79AA76535679BC" xlink:to="loc_srt_MaximumMember_6D3FCE2B977956728D02AABB33138485" 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_EC3089D28F795B609592CD054748F8FC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_C859DBC3E2695A0FA741599A1F26CC84" xlink:to="loc_us-gaap_AwardTypeAxis_EC3089D28F795B609592CD054748F8FC" 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_43F2C7696AB0E212A1693D55BDDCCD20_311BB24B425E582FA75BEA1D866A27C0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_EC3089D28F795B609592CD054748F8FC" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_43F2C7696AB0E212A1693D55BDDCCD20_311BB24B425E582FA75BEA1D866A27C0" 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_D669E9FE3DF95B2FACC35F9E21F774E0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_EC3089D28F795B609592CD054748F8FC" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D669E9FE3DF95B2FACC35F9E21F774E0" 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_EC03B59EF6B05BB3841BCC3003B7C225" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D669E9FE3DF95B2FACC35F9E21F774E0" xlink:to="loc_us-gaap_RestrictedStockMember_EC03B59EF6B05BB3841BCC3003B7C225" 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_3962CF27F7D25E9EA57FA3612EF212B6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3756FA0FA3E15DC4A050FE5A4FF2E2C5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3962CF27F7D25E9EA57FA3612EF212B6" 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_5541FE1425245B38996E1E6F3A7B9B02" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3962CF27F7D25E9EA57FA3612EF212B6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_5541FE1425245B38996E1E6F3A7B9B02" 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_FBBBAA886DEF543EBFB4CA2D456659EA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3962CF27F7D25E9EA57FA3612EF212B6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_FBBBAA886DEF543EBFB4CA2D456659EA" 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_ED16CCDB40135E5FA558A876F2EA7DDD" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3962CF27F7D25E9EA57FA3612EF212B6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_ED16CCDB40135E5FA558A876F2EA7DDD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_74788407617958E2B28F73DFA4794B50" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3962CF27F7D25E9EA57FA3612EF212B6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_74788407617958E2B28F73DFA4794B50" 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_288A185521A45194B6C1E572B941350F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3756FA0FA3E15DC4A050FE5A4FF2E2C5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_288A185521A45194B6C1E572B941350F" 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_22AC7C4AB82558049E5D2F0A04ED4941" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_288A185521A45194B6C1E572B941350F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_22AC7C4AB82558049E5D2F0A04ED4941" 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_19A089158F565F179D1A8AA18D1CC379" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_288A185521A45194B6C1E572B941350F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_19A089158F565F179D1A8AA18D1CC379" 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_D90D8224CD305FAB9983F5C14BB70987" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_288A185521A45194B6C1E572B941350F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_D90D8224CD305FAB9983F5C14BB70987" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_773BFC93F084514F94C183B2894E9B11" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_288A185521A45194B6C1E572B941350F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_773BFC93F084514F94C183B2894E9B11" 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_7A2D5A539AF15D0CA45232714BCA3612" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3756FA0FA3E15DC4A050FE5A4FF2E2C5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_7A2D5A539AF15D0CA45232714BCA3612" 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_F91C01C4CB2153AD81F01EF6120AD972" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3756FA0FA3E15DC4A050FE5A4FF2E2C5" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_F91C01C4CB2153AD81F01EF6120AD972" 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_B53D97DCCCEB51D2A96A649903307B75" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3756FA0FA3E15DC4A050FE5A4FF2E2C5" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_B53D97DCCCEB51D2A96A649903307B75" 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_B41B6867D3525D568BA9603CDA036F4B" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_3756FA0FA3E15DC4A050FE5A4FF2E2C5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_B41B6867D3525D568BA9603CDA036F4B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/StockBasedCompensationTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfCashFlows" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfComprehensiveIncomeLoss" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfComprehensiveIncomeLossParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfOperations" 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_A5D804CD539A0028B87565DB6B2848C5" 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_0044D930A431A6D89D9965DB6B264F1D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_StatementTable_0044D930A431A6D89D9965DB6B264F1D" 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_C5BEC1927459B7898F0265DB6B26F579" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0044D930A431A6D89D9965DB6B264F1D" xlink:to="loc_srt_ProductOrServiceAxis_C5BEC1927459B7898F0265DB6B26F579" 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_CC4D57436DAF6AB8B83765DB6B27CCB8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_C5BEC1927459B7898F0265DB6B26F579" xlink:to="loc_srt_ProductsAndServicesDomain_CC4D57436DAF6AB8B83765DB6B27CCB8_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_CC4D57436DAF6AB8B83765DB6B27CCB8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_C5BEC1927459B7898F0265DB6B26F579" xlink:to="loc_srt_ProductsAndServicesDomain_CC4D57436DAF6AB8B83765DB6B27CCB8" 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_71E8EA3FEFBF0B4CBE8065DB6B27B114" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_CC4D57436DAF6AB8B83765DB6B27CCB8" xlink:to="loc_us-gaap_ServiceMember_71E8EA3FEFBF0B4CBE8065DB6B27B114" 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_BD3C81BAB70BE0F91E5E65DB6B2759AB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_CC4D57436DAF6AB8B83765DB6B27CCB8" xlink:to="loc_us-gaap_ProductMember_BD3C81BAB70BE0F91E5E65DB6B2759AB" 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_5476A03889F4BBD5A5FA65DB6B285C1E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_RevenuesAbstract_5476A03889F4BBD5A5FA65DB6B285C1E" 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_D8227838DF558AA75FD065DB6B28DED9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_5476A03889F4BBD5A5FA65DB6B285C1E" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_D8227838DF558AA75FD065DB6B28DED9" 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_AA6575D79BD8F02E761D65DB6B286DCD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_CostOfRevenueAbstract_AA6575D79BD8F02E761D65DB6B286DCD" 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_C991BB0B2434F4D8DCD665DB6B28EE9A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_AA6575D79BD8F02E761D65DB6B286DCD" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_C991BB0B2434F4D8DCD665DB6B28EE9A" 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_ADC98547560432D286DB65DB6B2E8E95" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_ADC98547560432D286DB65DB6B2E8E95" xlink:type="arc" />
    <link:loc xlink:href="clh-20190331.xsd#clh_AccretionOfEnvironmentalLiabilities" xlink:label="loc_clh_AccretionOfEnvironmentalLiabilities_3D0788831DB7A65C0AED65DB6B2E031C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_clh_AccretionOfEnvironmentalLiabilities_3D0788831DB7A65C0AED65DB6B2E031C" 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_F97D02B9485DE82FEF6465DB6B2ED590" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_F97D02B9485DE82FEF6465DB6B2ED590" 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_C6F6912569995B300F4965DB6B2F6C24" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_OperatingIncomeLoss_C6F6912569995B300F4965DB6B2F6C24" 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_B85B5DCFCADFE7A72B3165DB6B2F6E28" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_B85B5DCFCADFE7A72B3165DB6B2F6E28" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_858EEAEBF2EE1F271A4365DB6B2F2F84" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_858EEAEBF2EE1F271A4365DB6B2F2F84" 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_0DF466019D9919A9F65C65DB6B2FF0CD" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_0DF466019D9919A9F65C65DB6B2FF0CD" 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_E468609A210F3C62E4B265DB6B305145" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_E468609A210F3C62E4B265DB6B305145" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_4B638B5C007757B93DEE65DB6B30437F" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_ProfitLoss_4B638B5C007757B93DEE65DB6B30437F" 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_3819323AE15C7B7C659365DB6B311D9C" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_EarningsPerShareAbstract_3819323AE15C7B7C659365DB6B311D9C" 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_80083B2C4D0CE5BC0B8E65DB6B310A14" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_3819323AE15C7B7C659365DB6B311D9C" xlink:to="loc_us-gaap_EarningsPerShareBasic_80083B2C4D0CE5BC0B8E65DB6B310A14" 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_18B7F5217CC4FC5C100E65DB6B312D48" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_3819323AE15C7B7C659365DB6B311D9C" xlink:to="loc_us-gaap_EarningsPerShareDiluted_18B7F5217CC4FC5C100E65DB6B312D48" 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_9A02C9995CAA1ACC04AB65DB6B3111CD" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_9A02C9995CAA1ACC04AB65DB6B3111CD" 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_6F8189EC1B6C3B89CF5965DB6B318535" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A5D804CD539A0028B87565DB6B2848C5" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_6F8189EC1B6C3B89CF5965DB6B318535" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfOperationsParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfStockholdersEquity" 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_338A92F9E98F82C8D3882234A5B365D9" 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_C66A2FAC1ECF4A47F3362234A5B13D42" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_338A92F9E98F82C8D3882234A5B365D9" xlink:to="loc_us-gaap_StatementTable_C66A2FAC1ECF4A47F3362234A5B13D42" 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_C92F3ED3C0349F569BC22234A5B1969D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_C66A2FAC1ECF4A47F3362234A5B13D42" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_C92F3ED3C0349F569BC22234A5B1969D" 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_1156AD7F0D9B5CB7B4B22234A5B20829_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_C92F3ED3C0349F569BC22234A5B1969D" xlink:to="loc_us-gaap_EquityComponentDomain_1156AD7F0D9B5CB7B4B22234A5B20829_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_1156AD7F0D9B5CB7B4B22234A5B20829" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_C92F3ED3C0349F569BC22234A5B1969D" xlink:to="loc_us-gaap_EquityComponentDomain_1156AD7F0D9B5CB7B4B22234A5B20829" 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_62BD56B1DA0DF179EFFA2234A5B2C8A7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1156AD7F0D9B5CB7B4B22234A5B20829" xlink:to="loc_us-gaap_CommonStockMember_62BD56B1DA0DF179EFFA2234A5B2C8A7" 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_EABBD2B8B102CFD1C0272234A5B3F6E3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1156AD7F0D9B5CB7B4B22234A5B20829" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_EABBD2B8B102CFD1C0272234A5B3F6E3" 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_C2338A21FA2D1B9C8DBA2234A5B378B8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1156AD7F0D9B5CB7B4B22234A5B20829" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_C2338A21FA2D1B9C8DBA2234A5B378B8" 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_D06CEBBDB11276CD677D2234A5B355B6" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1156AD7F0D9B5CB7B4B22234A5B20829" xlink:to="loc_us-gaap_RetainedEarningsMember_D06CEBBDB11276CD677D2234A5B355B6" 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_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_338A92F9E98F82C8D3882234A5B365D9" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_B64D1B19604EA6FD68942234A5B3A827" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_B64D1B19604EA6FD68942234A5B3A827" 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_0A55B5656B89922761F42234A5B4C5FC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_SharesIssued_0A55B5656B89922761F42234A5B4C5FC" 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_E9C2764A34F660931B5A2234A5B4606E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_E9C2764A34F660931B5A2234A5B4606E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_713130CCA203155783DB2234A5B454C8" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_ProfitLoss_713130CCA203155783DB2234A5B454C8" 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_8D1146632330D68EA9472234A5B49E2F" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_8D1146632330D68EA9472234A5B49E2F" 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_9D0424B0E3571674C3952234A5B42EDD" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_9D0424B0E3571674C3952234A5B42EDD" 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_6BA229C8765535A906652234A5B565D1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_6BA229C8765535A906652234A5B565D1" 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_87E8E65817F7029483D92234A5B59D20" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_87E8E65817F7029483D92234A5B59D20" 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_3D6B912158B7B035356D2234A5B53840" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_3D6B912158B7B035356D2234A5B53840" 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_18B94B99632BEBB62CF32234A5B55BEA" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_AE5DE6412FDEFD6BBA632234A5B3A77A" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_18B94B99632BEBB62CF32234A5B55BEA" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.cleanharbors.com/role/UnauditedConsolidatedStatementsOfStockholdersEquityParenthetical" xlink:type="extended" />
</link:linkbase>