<?xml version="1.0" encoding="US-ASCII"?>
<!--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://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncements" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncements" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsAccountsReceivableAndAllowanceForDoubtfulAccountsDetails" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncementsAccountsReceivableAndAllowanceForDoubtfulAccountsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsCapitalizedSoftwareDetails" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncementsCapitalizedSoftwareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsForeignCurrencyDetails" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncementsForeignCurrencyDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsGoodwillDetails" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncementsGoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsImpairmentOfLongLivedAssetsDetails" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncementsImpairmentOfLongLivedAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsPolicies" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncementsPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsPropertyAndEquipmentDetails" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncementsPropertyAndEquipmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsRevenueRecognitionDetails" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncementsRevenueRecognitionDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsTables" xlink:href="otex-20200630.xsd#AccountingPoliciesAndRecentAccountingPronouncementsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountsPayableAndAccruedLiabilities" xlink:href="otex-20200630.xsd#AccountsPayableAndAccruedLiabilities" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountsPayableAndAccruedLiabilitiesNarrativeDetails" xlink:href="otex-20200630.xsd#AccountsPayableAndAccruedLiabilitiesNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountsPayableAndAccruedLiabilitiesScheduleOfCurrentLiabilitiesDetails" xlink:href="otex-20200630.xsd#AccountsPayableAndAccruedLiabilitiesScheduleOfCurrentLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountsPayableAndAccruedLiabilitiesScheduleOfLongTermAccruedLiabilitiesDetails" xlink:href="otex-20200630.xsd#AccountsPayableAndAccruedLiabilitiesScheduleOfLongTermAccruedLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccountsPayableAndAccruedLiabilitiesTables" xlink:href="otex-20200630.xsd#AccountsPayableAndAccruedLiabilitiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccumulatedOtherComprehensiveIncome" xlink:href="otex-20200630.xsd#AccumulatedOtherComprehensiveIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccumulatedOtherComprehensiveIncomeDetails" xlink:href="otex-20200630.xsd#AccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AccumulatedOtherComprehensiveIncomeTables" xlink:href="otex-20200630.xsd#AccumulatedOtherComprehensiveIncomeTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquiredIntangibleAssets" xlink:href="otex-20200630.xsd#AcquiredIntangibleAssets" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquiredIntangibleAssetsCalculationOfAcquiredIntangiblesByAssetClassDetails" xlink:href="otex-20200630.xsd#AcquiredIntangibleAssetsCalculationOfAcquiredIntangiblesByAssetClassDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquiredIntangibleAssetsCalculationOfEstimatedFutureAmortizationExpenseDetails" xlink:href="otex-20200630.xsd#AcquiredIntangibleAssetsCalculationOfEstimatedFutureAmortizationExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquiredIntangibleAssetsTables" xlink:href="otex-20200630.xsd#AcquiredIntangibleAssetsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/Acquisitions" xlink:href="otex-20200630.xsd#Acquisitions" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfCarboniteDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfCarboniteDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfCarbonitePreliminaryPurchasePriceAllocationDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfCarbonitePreliminaryPurchasePriceAllocationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfCarboniteUnauditedProFormaInformationDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfCarboniteUnauditedProFormaInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfCatalystRepositorySystemsIncDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfCatalystRepositorySystemsIncDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfCatalystRepositorySystemsIncPurchasePriceAllocationDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfCatalystRepositorySystemsIncPurchasePriceAllocationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfCovisintCorporationDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfCovisintCorporationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfDynamicSolutionsGroupIncTheFaxGuysDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfDynamicSolutionsGroupIncTheFaxGuysDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfGuidanceSoftwareDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfGuidanceSoftwareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfHightailDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfHightailDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfHightailPurchasePriceAllocationDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfHightailPurchasePriceAllocationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfLiaisonTechnologiesIncDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfLiaisonTechnologiesIncDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfLiaisonTechnologiesIncPurchasePriceAllocationDetailsDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfLiaisonTechnologiesIncPurchasePriceAllocationDetailsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfXmediusDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfXmediusDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAcquisitionOfXmediusPreliminaryPurchasePriceAllocationDetails" xlink:href="otex-20200630.xsd#AcquisitionsAcquisitionOfXmediusPreliminaryPurchasePriceAllocationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsAppraisalProceedingsDetails" xlink:href="otex-20200630.xsd#AcquisitionsAppraisalProceedingsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AcquisitionsTables" xlink:href="otex-20200630.xsd#AcquisitionsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AllowanceForDoubtfulAccounts" xlink:href="otex-20200630.xsd#AllowanceForDoubtfulAccounts" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AllowanceForDoubtfulAccountsChangesInCarryingAmountDetails" xlink:href="otex-20200630.xsd#AllowanceForDoubtfulAccountsChangesInCarryingAmountDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/AllowanceForDoubtfulAccountsTables" xlink:href="otex-20200630.xsd#AllowanceForDoubtfulAccountsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/BasisOfPresentation" xlink:href="otex-20200630.xsd#BasisOfPresentation" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/BasisOfPresentationAdditionalInformationDetails" xlink:href="otex-20200630.xsd#BasisOfPresentationAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/BasisOfPresentationLeaseDetails" xlink:href="otex-20200630.xsd#BasisOfPresentationLeaseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ConsolidatedBalanceSheets" xlink:href="otex-20200630.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="otex-20200630.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="otex-20200630.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="otex-20200630.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ConsolidatedStatementsOfComprehensiveIncomeParenthetical" xlink:href="otex-20200630.xsd#ConsolidatedStatementsOfComprehensiveIncomeParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ConsolidatedStatementsOfIncome" xlink:href="otex-20200630.xsd#ConsolidatedStatementsOfIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ConsolidatedStatementsOfShareholdersEquity" xlink:href="otex-20200630.xsd#ConsolidatedStatementsOfShareholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ConsolidatedStatementsOfShareholdersEquityParenthetical" xlink:href="otex-20200630.xsd#ConsolidatedStatementsOfShareholdersEquityParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/CoverPage" xlink:href="otex-20200630.xsd#CoverPage" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/DerivativeInstrumentsAndHedgingActivities" xlink:href="otex-20200630.xsd#DerivativeInstrumentsAndHedgingActivities" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/DerivativeInstrumentsAndHedgingActivitiesEffectsOnIncomeAndOtherComprehensiveIncomeOciDetails" xlink:href="otex-20200630.xsd#DerivativeInstrumentsAndHedgingActivitiesEffectsOnIncomeAndOtherComprehensiveIncomeOciDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/DerivativeInstrumentsAndHedgingActivitiesFairValueInCondensedConsolidatedBalanceSheetsDetails" xlink:href="otex-20200630.xsd#DerivativeInstrumentsAndHedgingActivitiesFairValueInCondensedConsolidatedBalanceSheetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/DerivativeInstrumentsAndHedgingActivitiesTables" xlink:href="otex-20200630.xsd#DerivativeInstrumentsAndHedgingActivitiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/EarningsPerShare" xlink:href="otex-20200630.xsd#EarningsPerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/EarningsPerShareDetails" xlink:href="otex-20200630.xsd#EarningsPerShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/EarningsPerShareTables" xlink:href="otex-20200630.xsd#EarningsPerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/FairValueMeasurement" xlink:href="otex-20200630.xsd#FairValueMeasurement" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/FairValueMeasurementDetails" xlink:href="otex-20200630.xsd#FairValueMeasurementDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/FairValueMeasurementTables" xlink:href="otex-20200630.xsd#FairValueMeasurementTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/Goodwill" xlink:href="otex-20200630.xsd#Goodwill" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/GoodwillDetails" xlink:href="otex-20200630.xsd#GoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/GoodwillTables" xlink:href="otex-20200630.xsd#GoodwillTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/GuaranteesAndContingencies" xlink:href="otex-20200630.xsd#GuaranteesAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/GuaranteesAndContingenciesAdditionalInformationDetails" xlink:href="otex-20200630.xsd#GuaranteesAndContingenciesAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/GuaranteesAndContingenciesScheduleOfContractualObligationsWithMinimumPaymentsDetails" xlink:href="otex-20200630.xsd#GuaranteesAndContingenciesScheduleOfContractualObligationsWithMinimumPaymentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/GuaranteesAndContingenciesTables" xlink:href="otex-20200630.xsd#GuaranteesAndContingenciesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxes" xlink:href="otex-20200630.xsd#IncomeTaxes" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxesAdditionalInformationDetails" xlink:href="otex-20200630.xsd#IncomeTaxesAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxesChangesInBalanceOfGrossUnrecognizedTaxBenefitsDetails" xlink:href="otex-20200630.xsd#IncomeTaxesChangesInBalanceOfGrossUnrecognizedTaxBenefitsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxesComponentsOfDeferredTaxAssetsAndLiabilitiesDetails" xlink:href="otex-20200630.xsd#IncomeTaxesComponentsOfDeferredTaxAssetsAndLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxesComponentsOfIncomeTaxDetails" xlink:href="otex-20200630.xsd#IncomeTaxesComponentsOfIncomeTaxDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxesIncomeBeforeProvisionForIncomeTaxDetails" xlink:href="otex-20200630.xsd#IncomeTaxesIncomeBeforeProvisionForIncomeTaxDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxesIncomeTaxReconciliationDetails" xlink:href="otex-20200630.xsd#IncomeTaxesIncomeTaxReconciliationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxesInterestAccruedAndPenaltiesAccruedRelatedToIncomeTaxExpenseDetails" xlink:href="otex-20200630.xsd#IncomeTaxesInterestAccruedAndPenaltiesAccruedRelatedToIncomeTaxExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxesInterestAndPenaltiesRelatedToLiabilitiesForIncomeTaxExpenseDetails" xlink:href="otex-20200630.xsd#IncomeTaxesInterestAndPenaltiesRelatedToLiabilitiesForIncomeTaxExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/IncomeTaxesTables" xlink:href="otex-20200630.xsd#IncomeTaxesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/Leases" xlink:href="otex-20200630.xsd#Leases" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/LeasesAdditionalInformationDetails" xlink:href="otex-20200630.xsd#LeasesAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/LeasesLeaseCostsAndOtherInformationDetails" xlink:href="otex-20200630.xsd#LeasesLeaseCostsAndOtherInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/LeasesMaturityOfLeaseLiabilitiesDetails" xlink:href="otex-20200630.xsd#LeasesMaturityOfLeaseLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/LeasesTables" xlink:href="otex-20200630.xsd#LeasesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/LongTermDebt" xlink:href="otex-20200630.xsd#LongTermDebt" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/LongTermDebtAdditionalInformationDetails" xlink:href="otex-20200630.xsd#LongTermDebtAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/LongTermDebtScheduleOfLongTermDebtDetails" xlink:href="otex-20200630.xsd#LongTermDebtScheduleOfLongTermDebtDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/LongTermDebtSeniorUnsecuredFixedRateNotesDetails" xlink:href="otex-20200630.xsd#LongTermDebtSeniorUnsecuredFixedRateNotesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/LongTermDebtTables" xlink:href="otex-20200630.xsd#LongTermDebtTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/OtherAssets" xlink:href="otex-20200630.xsd#OtherAssets" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/OtherAssetsAdditionalInformationDetails" xlink:href="otex-20200630.xsd#OtherAssetsAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/OtherAssetsScheduleDetails" xlink:href="otex-20200630.xsd#OtherAssetsScheduleDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/OtherAssetsTables" xlink:href="otex-20200630.xsd#OtherAssetsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/OtherIncomeExpenseNet" xlink:href="otex-20200630.xsd#OtherIncomeExpenseNet" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/OtherIncomeExpenseNetAdditionalInformationDetails" xlink:href="otex-20200630.xsd#OtherIncomeExpenseNetAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/OtherIncomeExpenseNetScheduleOfOtherIncomeExpenseNetDetails" xlink:href="otex-20200630.xsd#OtherIncomeExpenseNetScheduleOfOtherIncomeExpenseNetDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/OtherIncomeExpenseNetTables" xlink:href="otex-20200630.xsd#OtherIncomeExpenseNetTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefits" xlink:href="otex-20200630.xsd#PensionPlansAndOtherPostRetirementBenefits" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsAdditionalInformationDetails" xlink:href="otex-20200630.xsd#PensionPlansAndOtherPostRetirementBenefitsAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsAnticipatedPensionPaymentsUnderPensionPlansDetails" xlink:href="otex-20200630.xsd#PensionPlansAndOtherPostRetirementBenefitsAnticipatedPensionPaymentsUnderPensionPlansDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsComponentsOfNetPensionExpenseDetails" xlink:href="otex-20200630.xsd#PensionPlansAndOtherPostRetirementBenefitsComponentsOfNetPensionExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsScheduleOfChangeInBenefitObligationDetails" xlink:href="otex-20200630.xsd#PensionPlansAndOtherPostRetirementBenefitsScheduleOfChangeInBenefitObligationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsScheduleOfDefinedBenefitPlansAndLongTermEmployeeBenefitObligationsDetails" xlink:href="otex-20200630.xsd#PensionPlansAndOtherPostRetirementBenefitsScheduleOfDefinedBenefitPlansAndLongTermEmployeeBenefitObligationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsScheduleOfWeightedAverageKeyAssumptionsUsedForPensionPlansDetails" xlink:href="otex-20200630.xsd#PensionPlansAndOtherPostRetirementBenefitsScheduleOfWeightedAverageKeyAssumptionsUsedForPensionPlansDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsTables" xlink:href="otex-20200630.xsd#PensionPlansAndOtherPostRetirementBenefitsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PropertyAndEquipment" xlink:href="otex-20200630.xsd#PropertyAndEquipment" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PropertyAndEquipmentDetails" xlink:href="otex-20200630.xsd#PropertyAndEquipmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/PropertyAndEquipmentTables" xlink:href="otex-20200630.xsd#PropertyAndEquipmentTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/RelatedPartyTransactions" xlink:href="otex-20200630.xsd#RelatedPartyTransactions" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/RelatedPartyTransactionsDetails" xlink:href="otex-20200630.xsd#RelatedPartyTransactionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/Revenues" xlink:href="otex-20200630.xsd#Revenues" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/RevenuesContractBalancesDetails" xlink:href="otex-20200630.xsd#RevenuesContractBalancesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/RevenuesDisaggregationOfRevenueDetails" xlink:href="otex-20200630.xsd#RevenuesDisaggregationOfRevenueDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/RevenuesIncrementalCostsOfObtainingContractWithCustomerDetails" xlink:href="otex-20200630.xsd#RevenuesIncrementalCostsOfObtainingContractWithCustomerDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/RevenuesTables" xlink:href="otex-20200630.xsd#RevenuesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/RevenuesTransactionPriceAllocatedToRemainingPerformanceObligationsDetails" xlink:href="otex-20200630.xsd#RevenuesTransactionPriceAllocatedToRemainingPerformanceObligationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SegmentInformation" xlink:href="otex-20200630.xsd#SegmentInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SegmentInformationAdditionalInformationDetails" xlink:href="otex-20200630.xsd#SegmentInformationAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SegmentInformationEntityWideDisclosureOnGeographicAreasLongLivedAssetsInIndividualForeignCountriesByCountryDetails" xlink:href="otex-20200630.xsd#SegmentInformationEntityWideDisclosureOnGeographicAreasLongLivedAssetsInIndividualForeignCountriesByCountryDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SegmentInformationRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaDetails" xlink:href="otex-20200630.xsd#SegmentInformationRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SegmentInformationTables" xlink:href="otex-20200630.xsd#SegmentInformationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPayments" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPayments" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsAdditionalInformationDetails" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsLongTermIncentivePlansDetails" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsLongTermIncentivePlansDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsRsusDsusAndEsppDetails" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsRsusDsusAndEsppDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsScheduleOfOutstandingStockOptionsActivityDetails" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsScheduleOfOutstandingStockOptionsActivityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsScheduleOfShareBasedPaymentsDetails" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsScheduleOfShareBasedPaymentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsScheduleOfWeightedAverageFairValueOfOptionsAndWeightedAverageAssumptionsUsedDetails" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsScheduleOfWeightedAverageFairValueOfOptionsAndWeightedAverageAssumptionsUsedDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsSummaryOfInformationRegardingStockOptionsOutstandingDetails" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsSummaryOfInformationRegardingStockOptionsOutstandingDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsSummaryOfOutstandingStockOptionsNarrativeDetails" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsSummaryOfOutstandingStockOptionsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsSummaryOfStockOptionsOutstandingUnderVariousStockOptionPlansDetails" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsSummaryOfStockOptionsOutstandingUnderVariousStockOptionPlansDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsTables" xlink:href="otex-20200630.xsd#ShareCapitalOptionPlansAndShareBasedPaymentsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SpecialChargesRecoveries" xlink:href="otex-20200630.xsd#SpecialChargesRecoveries" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SpecialChargesRecoveriesAdditionalInformationDetails" xlink:href="otex-20200630.xsd#SpecialChargesRecoveriesAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SpecialChargesRecoveriesScheduleOfRestructuringReserveDetails" xlink:href="otex-20200630.xsd#SpecialChargesRecoveriesScheduleOfRestructuringReserveDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SpecialChargesRecoveriesScheduleOfSpecialChargesRelatedToRestructuringPlanDetails" xlink:href="otex-20200630.xsd#SpecialChargesRecoveriesScheduleOfSpecialChargesRelatedToRestructuringPlanDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SpecialChargesRecoveriesTables" xlink:href="otex-20200630.xsd#SpecialChargesRecoveriesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SubsequentEvents" xlink:href="otex-20200630.xsd#SubsequentEvents" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SubsequentEventsDetails" xlink:href="otex-20200630.xsd#SubsequentEventsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SupplementalCashFlowDisclosures" xlink:href="otex-20200630.xsd#SupplementalCashFlowDisclosures" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SupplementalCashFlowDisclosuresDetails" xlink:href="otex-20200630.xsd#SupplementalCashFlowDisclosuresDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://opentext.com/role/SupplementalCashFlowDisclosuresTables" xlink:href="otex-20200630.xsd#SupplementalCashFlowDisclosuresTables" 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://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncements" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsAccountsReceivableAndAllowanceForDoubtfulAccountsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsCapitalizedSoftwareDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0BB233190A20CBB85CF55F1CF0E20E16" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_56B8F095A6F61A1FD0C15F1CF0DFCDE0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0BB233190A20CBB85CF55F1CF0E20E16" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_56B8F095A6F61A1FD0C15F1CF0DFCDE0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_C39893000FB161F5C6175F1CF0E03E5D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_56B8F095A6F61A1FD0C15F1CF0DFCDE0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_C39893000FB161F5C6175F1CF0E03E5D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3E563370AD6F0356D62A5F1CF0E06834_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_C39893000FB161F5C6175F1CF0E03E5D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3E563370AD6F0356D62A5F1CF0E06834_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3E563370AD6F0356D62A5F1CF0E06834" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_C39893000FB161F5C6175F1CF0E03E5D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3E563370AD6F0356D62A5F1CF0E06834" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CapitalizedSoftwareMember" xlink:label="loc_otex_CapitalizedSoftwareMember_DD073F6E44D5863F96AF5F1CF0E0A064" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3E563370AD6F0356D62A5F1CF0E06834" xlink:to="loc_otex_CapitalizedSoftwareMember_DD073F6E44D5863F96AF5F1CF0E0A064" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_9F1D761BCEC0A58AD4C35F1CF0E02C1A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_56B8F095A6F61A1FD0C15F1CF0DFCDE0" xlink:to="loc_srt_RangeAxis_9F1D761BCEC0A58AD4C35F1CF0E02C1A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_A6DEB1B892964B980E235F1CF0E11435_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_9F1D761BCEC0A58AD4C35F1CF0E02C1A" xlink:to="loc_srt_RangeMember_A6DEB1B892964B980E235F1CF0E11435_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_A6DEB1B892964B980E235F1CF0E11435" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_9F1D761BCEC0A58AD4C35F1CF0E02C1A" xlink:to="loc_srt_RangeMember_A6DEB1B892964B980E235F1CF0E11435" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_EF4938706BB2624EE5375F1CF0E1BCB8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_A6DEB1B892964B980E235F1CF0E11435" xlink:to="loc_srt_MinimumMember_EF4938706BB2624EE5375F1CF0E1BCB8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_C4318A26F7EEE1593ACE5F1CF0E18F56" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_A6DEB1B892964B980E235F1CF0E11435" xlink:to="loc_srt_MaximumMember_C4318A26F7EEE1593ACE5F1CF0E18F56" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_AD6EEE8FFBE4951F0D0D5F1CF0E2DC7C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0BB233190A20CBB85CF55F1CF0E20E16" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_AD6EEE8FFBE4951F0D0D5F1CF0E2DC7C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedComputerSoftwareGross" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareGross_0B7A523D7F095202138C5F1CF0E234CE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0BB233190A20CBB85CF55F1CF0E20E16" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareGross_0B7A523D7F095202138C5F1CF0E234CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedComputerSoftwareAdditions" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareAdditions_951D4DAD793BA0E6EA395F1CF0E2C433" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0BB233190A20CBB85CF55F1CF0E20E16" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareAdditions_951D4DAD793BA0E6EA395F1CF0E2C433" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsForeignCurrencyDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IntercompanyForeignCurrencyBalanceLineItems" xlink:label="loc_us-gaap_IntercompanyForeignCurrencyBalanceLineItems_EC50EA5451FA2BC385CD5F1CF361F479" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable" xlink:label="loc_us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable_658A3F77025423A3DDF55F1CF3600A40" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IntercompanyForeignCurrencyBalanceLineItems_EC50EA5451FA2BC385CD5F1CF361F479" xlink:to="loc_us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable_658A3F77025423A3DDF55F1CF3600A40" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_126960F282920AD7ADC25F1CF3604E24" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIntercompanyForeignCurrencyBalanceTable_658A3F77025423A3DDF55F1CF3600A40" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_126960F282920AD7ADC25F1CF3604E24" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_3175796473248925B3D05F1CF36024A2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_126960F282920AD7ADC25F1CF3604E24" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_3175796473248925B3D05F1CF36024A2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_3175796473248925B3D05F1CF36024A2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_126960F282920AD7ADC25F1CF3604E24" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_3175796473248925B3D05F1CF36024A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpenseMember" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_4A965B0C1980F0461AF15F1CF361CBBF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_3175796473248925B3D05F1CF36024A2" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_4A965B0C1980F0461AF15F1CF361CBBF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_A0C41DD63A5A083C4D9D5F1CF36127D0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IntercompanyForeignCurrencyBalanceLineItems_EC50EA5451FA2BC385CD5F1CF361F479" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_A0C41DD63A5A083C4D9D5F1CF36127D0" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsGoodwillDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsImpairmentOfLongLivedAssetsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsPolicies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsPropertyAndEquipmentDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_1B4B0E3F3861009514185F1CEC71A0BD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_44B345F400B3711C10905F1CEC6D7DFF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_1B4B0E3F3861009514185F1CEC71A0BD" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_44B345F400B3711C10905F1CEC6D7DFF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_8DA1B74816325F091B515F1CEC6DC264" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_44B345F400B3711C10905F1CEC6D7DFF" xlink:to="loc_srt_RangeAxis_8DA1B74816325F091B515F1CEC6DC264" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_2BC3ABAE770273693F7B5F1CEC6D76AA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_8DA1B74816325F091B515F1CEC6DC264" xlink:to="loc_srt_RangeMember_2BC3ABAE770273693F7B5F1CEC6D76AA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_2BC3ABAE770273693F7B5F1CEC6D76AA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_8DA1B74816325F091B515F1CEC6DC264" xlink:to="loc_srt_RangeMember_2BC3ABAE770273693F7B5F1CEC6D76AA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_C85FCA90CB58657F1E025F1CEC6EB82A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2BC3ABAE770273693F7B5F1CEC6D76AA" xlink:to="loc_srt_MinimumMember_C85FCA90CB58657F1E025F1CEC6EB82A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_9F8B1CDE403D080EB2A85F1CEC6E4340" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2BC3ABAE770273693F7B5F1CEC6D76AA" xlink:to="loc_srt_MaximumMember_9F8B1CDE403D080EB2A85F1CEC6E4340" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_FE09F31BC754FAA2AAA55F1CEC6ED1A0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_44B345F400B3711C10905F1CEC6D7DFF" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_FE09F31BC754FAA2AAA55F1CEC6ED1A0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_FE09F31BC754FAA2AAA55F1CEC6ED1A0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_FE09F31BC754FAA2AAA55F1CEC6ED1A0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_2FD1D60993F87E75B0AE5F1CEC6F6548" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_2FD1D60993F87E75B0AE5F1CEC6F6548" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OfficeEquipmentMember" xlink:label="loc_us-gaap_OfficeEquipmentMember_F5AE33CE2E94EE157B595F1CEC6F882F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288" xlink:to="loc_us-gaap_OfficeEquipmentMember_F5AE33CE2E94EE157B595F1CEC6F882F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ComputerHardwareMember" xlink:label="loc_otex_ComputerHardwareMember_2ACE349D80F1EB38DE405F1CEC6F1AD3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288" xlink:to="loc_otex_ComputerHardwareMember_2ACE349D80F1EB38DE405F1CEC6F1AD3" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ComputerSoftwareMember" xlink:label="loc_otex_ComputerSoftwareMember_AD3F59A3188CE6B502015F1CEC70816B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288" xlink:to="loc_otex_ComputerSoftwareMember_AD3F59A3188CE6B502015F1CEC70816B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CapitalizedSoftwareMember" xlink:label="loc_otex_CapitalizedSoftwareMember_448EBECF3E4B269454C05F1CEC700254" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288" xlink:to="loc_otex_CapitalizedSoftwareMember_448EBECF3E4B269454C05F1CEC700254" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_8409A6A70C06209678ED5F1CEC7016BE" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_8409A6A70C06209678ED5F1CEC7016BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_6B9508D6CF8F349D13F95F1CEC713271" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5CC1974435A26DE8F0505F1CEC6F0288" xlink:to="loc_us-gaap_BuildingMember_6B9508D6CF8F349D13F95F1CEC713271" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_2DCC2B6862DBCDF479935F1CEC712990" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_1B4B0E3F3861009514185F1CEC71A0BD" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_2DCC2B6862DBCDF479935F1CEC712990" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TangibleAssetImpairmentCharges" xlink:label="loc_us-gaap_TangibleAssetImpairmentCharges_167399BADC43A2A6EBF05F1CEC7155CB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_1B4B0E3F3861009514185F1CEC71A0BD" xlink:to="loc_us-gaap_TangibleAssetImpairmentCharges_167399BADC43A2A6EBF05F1CEC7155CB" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsRevenueRecognitionDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_2F44CFAA99AE6860501D5F1CF1D46093" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_05E71426CEE32D5FB8B55F1CF1D39853" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_2F44CFAA99AE6860501D5F1CF1D46093" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_05E71426CEE32D5FB8B55F1CF1D39853" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_B2A334229C8D67AB1E1D5F1CF1D3BEF7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_05E71426CEE32D5FB8B55F1CF1D39853" xlink:to="loc_srt_RangeAxis_B2A334229C8D67AB1E1D5F1CF1D3BEF7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_B3CD4AB5970476E021925F1CF1D3D9C8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_B2A334229C8D67AB1E1D5F1CF1D3BEF7" xlink:to="loc_srt_RangeMember_B3CD4AB5970476E021925F1CF1D3D9C8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_B3CD4AB5970476E021925F1CF1D3D9C8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_B2A334229C8D67AB1E1D5F1CF1D3BEF7" xlink:to="loc_srt_RangeMember_B3CD4AB5970476E021925F1CF1D3D9C8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_14B3233813DC2CE5710D5F1CF1D350A6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_B3CD4AB5970476E021925F1CF1D3D9C8" xlink:to="loc_srt_MinimumMember_14B3233813DC2CE5710D5F1CF1D350A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_6D4608FF706658D4A0A35F1CF1D4DFBE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_B3CD4AB5970476E021925F1CF1D3D9C8" xlink:to="loc_srt_MaximumMember_6D4608FF706658D4A0A35F1CF1D4DFBE" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ContractwithCustomerRightofReturnPeriod" xlink:label="loc_otex_ContractwithCustomerRightofReturnPeriod_2081B5877A66953455B35F1CF1D4D553" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_2F44CFAA99AE6860501D5F1CF1D46093" xlink:to="loc_otex_ContractwithCustomerRightofReturnPeriod_2081B5877A66953455B35F1CF1D4D553" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_RevenueFromContractWithCustomerPaymentPeriod" xlink:label="loc_otex_RevenueFromContractWithCustomerPaymentPeriod_657719CE1E54442CCC2A5F1CF1D5E3B8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_2F44CFAA99AE6860501D5F1CF1D46093" xlink:to="loc_otex_RevenueFromContractWithCustomerPaymentPeriod_657719CE1E54442CCC2A5F1CF1D5E3B8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuePerformanceObligationDescriptionOfTiming" xlink:label="loc_us-gaap_RevenuePerformanceObligationDescriptionOfTiming_99F3FCFB8FA84D00CD205F1CF1D54BE7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_2F44CFAA99AE6860501D5F1CF1D46093" xlink:to="loc_us-gaap_RevenuePerformanceObligationDescriptionOfTiming_99F3FCFB8FA84D00CD205F1CF1D54BE7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedContractCostAmortizationPeriod" xlink:label="loc_us-gaap_CapitalizedContractCostAmortizationPeriod_B54F9112073073E77F8C5F1CF1D5867B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_2F44CFAA99AE6860501D5F1CF1D46093" xlink:to="loc_us-gaap_CapitalizedContractCostAmortizationPeriod_B54F9112073073E77F8C5F1CF1D5867B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AccountingPoliciesAndRecentAccountingPronouncementsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountsPayableAndAccruedLiabilities" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountsPayableAndAccruedLiabilitiesNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountsPayableAndAccruedLiabilitiesScheduleOfCurrentLiabilitiesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountsPayableAndAccruedLiabilitiesScheduleOfLongTermAccruedLiabilitiesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccountsPayableAndAccruedLiabilitiesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccumulatedOtherComprehensiveIncome" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_F7A8AB03565BF560A24E8330AE6685F4" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_A3223DB75EB491D6A8118330AE63DE54" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_F7A8AB03565BF560A24E8330AE6685F4" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_A3223DB75EB491D6A8118330AE63DE54" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_9330FC55C9FCDA5982C98330AE641937" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_A3223DB75EB491D6A8118330AE63DE54" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_9330FC55C9FCDA5982C98330AE641937" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_05B4097542E67B52C5C28330AE64FEB1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_9330FC55C9FCDA5982C98330AE641937" xlink:to="loc_us-gaap_EquityComponentDomain_05B4097542E67B52C5C28330AE64FEB1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_05B4097542E67B52C5C28330AE64FEB1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_9330FC55C9FCDA5982C98330AE641937" xlink:to="loc_us-gaap_EquityComponentDomain_05B4097542E67B52C5C28330AE64FEB1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_D4F60E09D169FA68390E834EB79769BE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_05B4097542E67B52C5C28330AE64FEB1" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_D4F60E09D169FA68390E834EB79769BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_E97DE1B90977B41D2973834EFE9304CE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_05B4097542E67B52C5C28330AE64FEB1" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_E97DE1B90977B41D2973834EFE9304CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_C72CA0B3E5975CD9455E834F593B923F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_05B4097542E67B52C5C28330AE64FEB1" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_C72CA0B3E5975CD9455E834F593B923F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_6154AB29AD6821F0CC80834FEEE41E00" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_05B4097542E67B52C5C28330AE64FEB1" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_6154AB29AD6821F0CC80834FEEE41E00" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_4C0A52B7731E652EF6748330AE65246D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_05B4097542E67B52C5C28330AE64FEB1" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_4C0A52B7731E652EF6748330AE65246D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_739A8FEB49F6A82F41688330AE666C62" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_F7A8AB03565BF560A24E8330AE6685F4" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_739A8FEB49F6A82F41688330AE666C62" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_42E066D1A6082B0518298330AE66113C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_739A8FEB49F6A82F41688330AE666C62" xlink:to="loc_us-gaap_StockholdersEquity_42E066D1A6082B0518298330AE66113C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_5FB2CE6D46172DC9CA7E8330AE66AEBC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_739A8FEB49F6A82F41688330AE666C62" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_5FB2CE6D46172DC9CA7E8330AE66AEBC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_C3F67E0AE723711D296D8330AE6795BA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_739A8FEB49F6A82F41688330AE666C62" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_C3F67E0AE723711D296D8330AE6795BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_16F930BC5736C3A730558330AE6765E4" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_739A8FEB49F6A82F41688330AE666C62" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_16F930BC5736C3A730558330AE6765E4" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AccumulatedOtherComprehensiveIncomeTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AcquiredIntangibleAssets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AcquiredIntangibleAssetsCalculationOfAcquiredIntangiblesByAssetClassDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_127406A3743979364A205F1CEED645BC" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:label="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_E2187AF145866ACA70135F1CEED44975" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_127406A3743979364A205F1CEED645BC" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_E2187AF145866ACA70135F1CEED44975" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6C5CFDD5603F18C7E78E5F1CEED594CE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_E2187AF145866ACA70135F1CEED44975" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6C5CFDD5603F18C7E78E5F1CEED594CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_672EC736B210B46A961E5F1CEED59238_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6C5CFDD5603F18C7E78E5F1CEED594CE" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_672EC736B210B46A961E5F1CEED59238_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_672EC736B210B46A961E5F1CEED59238" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6C5CFDD5603F18C7E78E5F1CEED594CE" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_672EC736B210B46A961E5F1CEED59238" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TechnologyAssetsMember" xlink:label="loc_otex_TechnologyAssetsMember_5C0F448180786B7523175F1CEED58369" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_672EC736B210B46A961E5F1CEED59238" xlink:to="loc_otex_TechnologyAssetsMember_5C0F448180786B7523175F1CEED58369" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerAssetsMember" xlink:label="loc_otex_CustomerAssetsMember_E8C2C3667DECB37644B75F1CEED659CC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_672EC736B210B46A961E5F1CEED59238" xlink:to="loc_otex_CustomerAssetsMember_E8C2C3667DECB37644B75F1CEED659CC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_41383106979C4D078BB55F1CEED66A75" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_127406A3743979364A205F1CEED645BC" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_41383106979C4D078BB55F1CEED66A75" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_5EB7E6B2D7EED98DAD435F1CEED6F165" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_41383106979C4D078BB55F1CEED66A75" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_5EB7E6B2D7EED98DAD435F1CEED6F165" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_B2E8566483EF60AF538C5F1CEED72FAC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_41383106979C4D078BB55F1CEED66A75" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_B2E8566483EF60AF538C5F1CEED72FAC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_6137745EDB18BF6E90135F1CEED7B4A2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_41383106979C4D078BB55F1CEED66A75" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_6137745EDB18BF6E90135F1CEED7B4A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsPeriodIncreaseDecrease_442603C112D134887B975F1CEED7A111" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_127406A3743979364A205F1CEED645BC" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsPeriodIncreaseDecrease_442603C112D134887B975F1CEED7A111" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_76D7566C5CE44F6F96EB5F1CEED7D7D5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_127406A3743979364A205F1CEED645BC" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_76D7566C5CE44F6F96EB5F1CEED7D7D5" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquiredIntangibleAssetsCalculationOfEstimatedFutureAmortizationExpenseDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AcquiredIntangibleAssetsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/Acquisitions" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfCarboniteDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_4395EA366D927AECA1C65F1CEB2907F2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_4395EA366D927AECA1C65F1CEB2907F2" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_AF7248A3EF5C29F130BC5F1CEB29FBEC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_4395EA366D927AECA1C65F1CEB2907F2" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_AF7248A3EF5C29F130BC5F1CEB29FBEC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C48D9800831C38320BD25F1CEB2AD33F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_AF7248A3EF5C29F130BC5F1CEB29FBEC" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C48D9800831C38320BD25F1CEB2AD33F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C48D9800831C38320BD25F1CEB2AD33F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_AF7248A3EF5C29F130BC5F1CEB29FBEC" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C48D9800831C38320BD25F1CEB2AD33F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CarboniteInc.Member" xlink:label="loc_otex_CarboniteInc.Member_2028EED44DCECA6BF5E65F1CEB2A9279" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C48D9800831C38320BD25F1CEB2AD33F" xlink:to="loc_otex_CarboniteInc.Member_2028EED44DCECA6BF5E65F1CEB2A9279" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_635CBCE66D791D48835E5F1CEB30852E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_635CBCE66D791D48835E5F1CEB30852E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_9050B6F501A1314534E25F1CEB30EC1A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_us-gaap_Goodwill_9050B6F501A1314534E25F1CEB30EC1A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount" xlink:label="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_6FBA3135FCBB19DC86E85F1CEB30A627" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_6FBA3135FCBB19DC86E85F1CEB30A627" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_B70D424C6BA385B07D605F1CEB311B36" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_B70D424C6BA385B07D605F1CEB311B36" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredRevenue" xlink:label="loc_otex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredRevenue_DB03483DDB8B3DD3693C5F1CEB315C7D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_otex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredRevenue_DB03483DDB8B3DD3693C5F1CEB315C7D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_342909096DF71B1FEAD25F1CEB313161" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_342909096DF71B1FEAD25F1CEB313161" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_5CA7CE63DA79575CA8AD5F1CEB314D2C" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_5CA7CE63DA79575CA8AD5F1CEB314D2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_E085F2D85F9D20D839455F1CEB312E23" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_E085F2D85F9D20D839455F1CEB312E23" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1C8EF61CE161DB26804C5F1CEB315456" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_63913DA3C998A599FE485F1CEB2FA407" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1C8EF61CE161DB26804C5F1CEB315456" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfCarbonitePreliminaryPurchasePriceAllocationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_5A9CE99245249E8C65825F1CF1E60249" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_5A9CE99245249E8C65825F1CF1E60249" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_FC335120D3F198E47F685F1CF1E69225" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_5A9CE99245249E8C65825F1CF1E60249" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_FC335120D3F198E47F685F1CF1E69225" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3DC948C469304312582A5F1CF1E786D9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FC335120D3F198E47F685F1CF1E69225" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3DC948C469304312582A5F1CF1E786D9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3DC948C469304312582A5F1CF1E786D9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FC335120D3F198E47F685F1CF1E69225" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3DC948C469304312582A5F1CF1E786D9" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CarboniteInc.Member" xlink:label="loc_otex_CarboniteInc.Member_14219C9AACDC7EB623C45F1CF1E745F9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3DC948C469304312582A5F1CF1E786D9" xlink:to="loc_otex_CarboniteInc.Member_14219C9AACDC7EB623C45F1CF1E745F9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6E2453E04EEFBED3FF0A5F1CF1E7F66C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_5A9CE99245249E8C65825F1CF1E60249" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6E2453E04EEFBED3FF0A5F1CF1E7F66C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5F02DB002D6C9655AE685F1CF1E806D3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6E2453E04EEFBED3FF0A5F1CF1E7F66C" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5F02DB002D6C9655AE685F1CF1E806D3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5F02DB002D6C9655AE685F1CF1E806D3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_6E2453E04EEFBED3FF0A5F1CF1E7F66C" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5F02DB002D6C9655AE685F1CF1E806D3" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerAssetsMember" xlink:label="loc_otex_CustomerAssetsMember_EF25C20C8BC9A2FD9A9C5F1CF1E8DEAE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5F02DB002D6C9655AE685F1CF1E806D3" xlink:to="loc_otex_CustomerAssetsMember_EF25C20C8BC9A2FD9A9C5F1CF1E8DEAE" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TechnologyAssetsMember" xlink:label="loc_otex_TechnologyAssetsMember_7F37999C8AE0BB2235295F1CF1E85E86" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5F02DB002D6C9655AE685F1CF1E806D3" xlink:to="loc_otex_TechnologyAssetsMember_7F37999C8AE0BB2235295F1CF1E85E86" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_6C40F3F5B566433DC8825F1CF1E9454C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_6C40F3F5B566433DC8825F1CF1E9454C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_4DDF0F6D3DE04163ECE25F1CF1E9CE66" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_4DDF0F6D3DE04163ECE25F1CF1E9CE66" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedRestrictedCashandEquivalents" xlink:label="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedRestrictedCashandEquivalents_0A8FDF7F313F87DAB1005F1CF1E9D7FF" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedRestrictedCashandEquivalents_0A8FDF7F313F87DAB1005F1CF1E9D7FF" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets" xlink:label="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_3C5E117F053085B420675F1CF1E91F38" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_3C5E117F053085B420675F1CF1E91F38" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_33AF6379249B46B49FC85F1CF1EA1EAE" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_33AF6379249B46B49FC85F1CF1EA1EAE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_17C11D9CB9D152A773015F1CF1EA03A8" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_17C11D9CB9D152A773015F1CF1EA03A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_436A58C78D383EF3A42A5F1CF1EA59AE" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_436A58C78D383EF3A42A5F1CF1EA59AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_7C6803B8BD9995E6BAE75F1CF1EA6ACA" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_us-gaap_Goodwill_7C6803B8BD9995E6BAE75F1CF1EA6ACA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_84CF5A23A6EB855636C95F1CF1EB5D4F" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4FFEE592212830CCFC825F1CF1E9E817" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_84CF5A23A6EB855636C95F1CF1EB5D4F" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfCarboniteUnauditedProFormaInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F361E8198A1CCDD707FEC0AF7E7E5E08" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F361E8198A1CCDD707FEC0AF7E7E5E08" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="loc_us-gaap_NonrecurringAdjustmentAxis_1FBEF55EE4386BC1F1D5C0AF7E7F4474" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F361E8198A1CCDD707FEC0AF7E7E5E08" xlink:to="loc_us-gaap_NonrecurringAdjustmentAxis_1FBEF55EE4386BC1F1D5C0AF7E7F4474" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="loc_us-gaap_NonrecurringAdjustmentDomain_A4A814BC43A691ADF063C0AF7E7FE38D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_NonrecurringAdjustmentAxis_1FBEF55EE4386BC1F1D5C0AF7E7F4474" xlink:to="loc_us-gaap_NonrecurringAdjustmentDomain_A4A814BC43A691ADF063C0AF7E7FE38D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="loc_us-gaap_NonrecurringAdjustmentDomain_A4A814BC43A691ADF063C0AF7E7FE38D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_NonrecurringAdjustmentAxis_1FBEF55EE4386BC1F1D5C0AF7E7F4474" xlink:to="loc_us-gaap_NonrecurringAdjustmentDomain_A4A814BC43A691ADF063C0AF7E7FE38D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AcquisitionRelatedCostsMember" xlink:label="loc_us-gaap_AcquisitionRelatedCostsMember_E2AE872082012E69A8DCC0AF7E8064A5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonrecurringAdjustmentDomain_A4A814BC43A691ADF063C0AF7E7FE38D" xlink:to="loc_us-gaap_AcquisitionRelatedCostsMember_E2AE872082012E69A8DCC0AF7E8064A5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_76B2A7FF64332DDC1352C0AF7E80D2AB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F361E8198A1CCDD707FEC0AF7E7E5E08" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_76B2A7FF64332DDC1352C0AF7E80D2AB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_37ADBA62CEFBB6DD2E75C0AF7E80D337_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_76B2A7FF64332DDC1352C0AF7E80D2AB" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_37ADBA62CEFBB6DD2E75C0AF7E80D337_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_37ADBA62CEFBB6DD2E75C0AF7E80D337" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_76B2A7FF64332DDC1352C0AF7E80D2AB" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_37ADBA62CEFBB6DD2E75C0AF7E80D337" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CarboniteInc.Member" xlink:label="loc_otex_CarboniteInc.Member_B823DFF94DFC7C04B184C0AF7E81B7B2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_37ADBA62CEFBB6DD2E75C0AF7E80D337" xlink:to="loc_otex_CarboniteInc.Member_B823DFF94DFC7C04B184C0AF7E81B7B2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_F356D410A437D63EA672C0AF7E86D020" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_F356D410A437D63EA672C0AF7E86D020" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_4EB1367F25ED684AE669C0AF7E875A35" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_4EB1367F25ED684AE669C0AF7E875A35" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessAcquisitionRestructuringandOtherAcquisitionRelatedCharges" xlink:label="loc_otex_BusinessAcquisitionRestructuringandOtherAcquisitionRelatedCharges_24D00A3CA2455CE6BF78C0AF7E875336" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_otex_BusinessAcquisitionRestructuringandOtherAcquisitionRelatedCharges_24D00A3CA2455CE6BF78C0AF7E875336" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_2A0E2949BB340EA09746C0AF7E879395" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_2A0E2949BB340EA09746C0AF7E879395" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_EC7E5936F8925CF32DCBC0AF7E88EC4E" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_EC7E5936F8925CF32DCBC0AF7E88EC4E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_433486431DE68E457376C0AF7E88A8FF" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_433486431DE68E457376C0AF7E88A8FF" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessAcquisitionProFormaExpense" xlink:label="loc_otex_BusinessAcquisitionProFormaExpense_3E74CD73A2F9388DE4A7C0AF7E88C2CB" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_otex_BusinessAcquisitionProFormaExpense_3E74CD73A2F9388DE4A7C0AF7E88C2CB" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessAcquisitionProFormaExpenseTax" xlink:label="loc_otex_BusinessAcquisitionProFormaExpenseTax_0886F3134D18FFCD44E9C0AF7E883B5F" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_otex_BusinessAcquisitionProFormaExpenseTax_0886F3134D18FFCD44E9C0AF7E883B5F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessAcquisitionProFormaExpenseAcceleratedVestingofEquityAwards" xlink:label="loc_otex_BusinessAcquisitionProFormaExpenseAcceleratedVestingofEquityAwards_470CDC9486DF78835B35C0AF7E88985E" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_otex_BusinessAcquisitionProFormaExpenseAcceleratedVestingofEquityAwards_470CDC9486DF78835B35C0AF7E88985E" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessAcquisitionProFormaExpenseTransactionFees" xlink:label="loc_otex_BusinessAcquisitionProFormaExpenseTransactionFees_6DECF18B31F049BB93BDC0AF7E880895" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_otex_BusinessAcquisitionProFormaExpenseTransactionFees_6DECF18B31F049BB93BDC0AF7E880895" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessAcquisitionProFormaExpenseExtinguishmentofDebtandInterestRateSwaps" xlink:label="loc_otex_BusinessAcquisitionProFormaExpenseExtinguishmentofDebtandInterestRateSwaps_8B19C874FEB929DAB476C0AF7E898236" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_otex_BusinessAcquisitionProFormaExpenseExtinguishmentofDebtandInterestRateSwaps_8B19C874FEB929DAB476C0AF7E898236" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessAcquisitionProFormaExpenseEmployeeSeveranceCost" xlink:label="loc_otex_BusinessAcquisitionProFormaExpenseEmployeeSeveranceCost_E0FCDB0D15553F499DDFC0AF7E89C3ED" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5C7C473A8FFA32A647D4C0AF7E8168C7" xlink:to="loc_otex_BusinessAcquisitionProFormaExpenseEmployeeSeveranceCost_E0FCDB0D15553F499DDFC0AF7E89C3ED" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfCatalystRepositorySystemsIncDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_63A1477A67C3B65EDA795F1CF367A9CB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_63A1477A67C3B65EDA795F1CF367A9CB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_DEE0E6B98DB8A4B9887A5F1CF36777D7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_63A1477A67C3B65EDA795F1CF367A9CB" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_DEE0E6B98DB8A4B9887A5F1CF36777D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_18279C049E5C86EAF6315F1CF36712F4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_DEE0E6B98DB8A4B9887A5F1CF36777D7" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_18279C049E5C86EAF6315F1CF36712F4_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_18279C049E5C86EAF6315F1CF36712F4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_DEE0E6B98DB8A4B9887A5F1CF36777D7" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_18279C049E5C86EAF6315F1CF36712F4" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CatalystRepositorySystemsIncMember" xlink:label="loc_otex_CatalystRepositorySystemsIncMember_2FEC5C55F6F504B49EF55F1CF368DCB0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_18279C049E5C86EAF6315F1CF36712F4" xlink:to="loc_otex_CatalystRepositorySystemsIncMember_2FEC5C55F6F504B49EF55F1CF368DCB0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_609619194028A169680C5F1CF3686A4A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_609619194028A169680C5F1CF3686A4A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_49A3DC4CC07ACF7EE4F25F1CF3685F82" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_49A3DC4CC07ACF7EE4F25F1CF3685F82" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_99E92252C9C24CA97DB25F1CF3691773" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_99E92252C9C24CA97DB25F1CF3691773" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_353A800FA8E5D231B8605F1CF369D3D6" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_Goodwill_353A800FA8E5D231B8605F1CF369D3D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount" xlink:label="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_766A0598FFD8871F68545F1CF369B438" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_766A0598FFD8871F68545F1CF369B438" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_DE015EDAEC48655483935F1CF369E4B6" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_DE015EDAEC48655483935F1CF369E4B6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_A3A112EE08F3C25ABB6D5F1CF36A3CA5" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_A3A112EE08F3C25ABB6D5F1CF36A3CA5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_B49B381EBF8BB87696A55F1CF36A996A" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_B49B381EBF8BB87696A55F1CF36A996A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_73C29480DBAA89CC08BE5F1CF36A0079" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_73C29480DBAA89CC08BE5F1CF36A0079" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_446166EC670CE11443E85F1CF36A6F08" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_251E6AE9621CD20317D85F1CF3686DFB" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_446166EC670CE11443E85F1CF36A6F08" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfCatalystRepositorySystemsIncPurchasePriceAllocationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_F0987FF922B614DCF0CA5F1CF3256A1A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_55EB0D1BB95572A93C185F1CF32387D6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F0987FF922B614DCF0CA5F1CF3256A1A" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_55EB0D1BB95572A93C185F1CF32387D6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_7385CB360A5F2BBADEC85F1CF32389D0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_55EB0D1BB95572A93C185F1CF32387D6" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_7385CB360A5F2BBADEC85F1CF32389D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8CF4FB8E0ED6105FA6C65F1CF3240895_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7385CB360A5F2BBADEC85F1CF32389D0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8CF4FB8E0ED6105FA6C65F1CF3240895_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8CF4FB8E0ED6105FA6C65F1CF3240895" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7385CB360A5F2BBADEC85F1CF32389D0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8CF4FB8E0ED6105FA6C65F1CF3240895" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CatalystRepositorySystemsIncMember" xlink:label="loc_otex_CatalystRepositorySystemsIncMember_F06DD8925A297B5F34FB5F1CF3242FB1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8CF4FB8E0ED6105FA6C65F1CF3240895" xlink:to="loc_otex_CatalystRepositorySystemsIncMember_F06DD8925A297B5F34FB5F1CF3242FB1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_B301A813AD062A3C8CE45F1CF3247344" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_55EB0D1BB95572A93C185F1CF32387D6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_B301A813AD062A3C8CE45F1CF3247344" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1A2E8AA32665E9C84F405F1CF324C505_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_B301A813AD062A3C8CE45F1CF3247344" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1A2E8AA32665E9C84F405F1CF324C505_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1A2E8AA32665E9C84F405F1CF324C505" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_B301A813AD062A3C8CE45F1CF3247344" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1A2E8AA32665E9C84F405F1CF324C505" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerAssetsMember" xlink:label="loc_otex_CustomerAssetsMember_69CA2824827F789714DE5F1CF32581C8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1A2E8AA32665E9C84F405F1CF324C505" xlink:to="loc_otex_CustomerAssetsMember_69CA2824827F789714DE5F1CF32581C8" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TechnologyAssetsMember" xlink:label="loc_otex_TechnologyAssetsMember_477FF1AAA878DF60F1EE5F1CF325A725" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1A2E8AA32665E9C84F405F1CF324C505" xlink:to="loc_otex_TechnologyAssetsMember_477FF1AAA878DF60F1EE5F1CF325A725" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_012C2E3725514D5FA1DF5F1CF32543E0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F0987FF922B614DCF0CA5F1CF3256A1A" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_012C2E3725514D5FA1DF5F1CF32543E0" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets" xlink:label="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_26C5E4A9D43E8118B0FF5F1CF3264FE1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F0987FF922B614DCF0CA5F1CF3256A1A" xlink:to="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_26C5E4A9D43E8118B0FF5F1CF3264FE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_26916AB02191A8A7923F5F1CF3262114" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F0987FF922B614DCF0CA5F1CF3256A1A" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_26916AB02191A8A7923F5F1CF3262114" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_40922EAD8660AAEE59995F1CF326C84A" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F0987FF922B614DCF0CA5F1CF3256A1A" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_40922EAD8660AAEE59995F1CF326C84A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_27CCDA6D0745326F43CA5F1CF326E5F8" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F0987FF922B614DCF0CA5F1CF3256A1A" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_27CCDA6D0745326F43CA5F1CF326E5F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_638BD757B7F578061E1B5F1CF3277FF8" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F0987FF922B614DCF0CA5F1CF3256A1A" xlink:to="loc_us-gaap_Goodwill_638BD757B7F578061E1B5F1CF3277FF8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_CD1CD3F9B3108CA47B705F1CF32705E0" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F0987FF922B614DCF0CA5F1CF3256A1A" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_CD1CD3F9B3108CA47B705F1CF32705E0" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfCovisintCorporationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_EBFD13B9B32B7BD2223FA70C654F93AD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_EBFD13B9B32B7BD2223FA70C654F93AD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_39FD1063011CBE42B66BA70C6550972D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_EBFD13B9B32B7BD2223FA70C654F93AD" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_39FD1063011CBE42B66BA70C6550972D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_47175FAE8A7851DB3812A70C655011EE_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_39FD1063011CBE42B66BA70C6550972D" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_47175FAE8A7851DB3812A70C655011EE_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_47175FAE8A7851DB3812A70C655011EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_39FD1063011CBE42B66BA70C6550972D" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_47175FAE8A7851DB3812A70C655011EE" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CovisintCorporationMember" xlink:label="loc_otex_CovisintCorporationMember_A858AC405052ED470E25A70C65519DFC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_47175FAE8A7851DB3812A70C655011EE" xlink:to="loc_otex_CovisintCorporationMember_A858AC405052ED470E25A70C65519DFC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_DA25EFD08C7133C3D7EDA70C65513D60" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_EBFD13B9B32B7BD2223FA70C654F93AD" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_DA25EFD08C7133C3D7EDA70C65513D60" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_51CD41FA74DC2DCF9F8CA70C6551422D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_DA25EFD08C7133C3D7EDA70C65513D60" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_51CD41FA74DC2DCF9F8CA70C6551422D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_51CD41FA74DC2DCF9F8CA70C6551422D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_DA25EFD08C7133C3D7EDA70C65513D60" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_51CD41FA74DC2DCF9F8CA70C6551422D" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerAssetsMember" xlink:label="loc_otex_CustomerAssetsMember_896DBA299C1B434169E7A70C65510503" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_51CD41FA74DC2DCF9F8CA70C6551422D" xlink:to="loc_otex_CustomerAssetsMember_896DBA299C1B434169E7A70C65510503" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TechnologyAssetsMember" xlink:label="loc_otex_TechnologyAssetsMember_A04A480FAA49E4C7F06DA70C65520D63" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_51CD41FA74DC2DCF9F8CA70C6551422D" xlink:to="loc_otex_TechnologyAssetsMember_A04A480FAA49E4C7F06DA70C65520D63" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_ADEFC5E622E8AB48157AA70C655202DB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_ADEFC5E622E8AB48157AA70C655202DB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_8BAECFF879614A39BD3AA70C65536EB8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_8BAECFF879614A39BD3AA70C65536EB8" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets" xlink:label="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_75CD383935C001F9C3E1A70C6553CDC0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:to="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_75CD383935C001F9C3E1A70C6553CDC0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_FA618A3A83B7619D5E73A70C6553B737" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_FA618A3A83B7619D5E73A70C6553B737" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_C290A56025F00AC9B002A70C6553FB4E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_C290A56025F00AC9B002A70C6553FB4E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_C9171E79DA25B98744D1A70C65537EC5" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_C9171E79DA25B98744D1A70C65537EC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_BEA8763497294D11E923A70C65541196" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:to="loc_us-gaap_Goodwill_BEA8763497294D11E923A70C65541196" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_036811846F16B6C5A563A70C65541659" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_036811846F16B6C5A563A70C65541659" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAcquiredFromAcquisition" xlink:label="loc_us-gaap_CashAcquiredFromAcquisition_2F7B8412FAA7D29C5FB8A70C6554C8CF" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_0BB4CD3A1ABD35C3F2C4A70C65527155" xlink:to="loc_us-gaap_CashAcquiredFromAcquisition_2F7B8412FAA7D29C5FB8A70C6554C8CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount" xlink:label="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_6A4005BDDFD039EF7E7BA70C6554D087" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:to="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_6A4005BDDFD039EF7E7BA70C6554D087" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_120E5CE6CF2AF2774B49A70C6554AC7D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_120E5CE6CF2AF2774B49A70C6554AC7D" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationSeparatelyRecognizedTransactionsAdjustmentDeferredRevenue" xlink:label="loc_otex_BusinessCombinationSeparatelyRecognizedTransactionsAdjustmentDeferredRevenue_CE264B638D79534DB034A75867325D4C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:to="loc_otex_BusinessCombinationSeparatelyRecognizedTransactionsAdjustmentDeferredRevenue_CE264B638D79534DB034A75867325D4C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_987D5AE840A4FD2B5D3BA70C65551762" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_987D5AE840A4FD2B5D3BA70C65551762" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_D87BD6DE02F5DEA3ADCCA70C655502EF" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_D87BD6DE02F5DEA3ADCCA70C655502EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_3EA89954D77FC6E3503EA70C65555389" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_7321664065E1F01BCB84A70C6552CF61" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_3EA89954D77FC6E3503EA70C65555389" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfDynamicSolutionsGroupIncTheFaxGuysDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_C39B0175B5B4E41105FE5F1CF205A349" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7C6B11F7664FC96AF1315F1CF2047664" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C39B0175B5B4E41105FE5F1CF205A349" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7C6B11F7664FC96AF1315F1CF2047664" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_1E2A14A1F36947B53E515F1CF2041431" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7C6B11F7664FC96AF1315F1CF2047664" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_1E2A14A1F36947B53E515F1CF2041431" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4B96A26AB989A500DFEE5F1CF2049FAF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1E2A14A1F36947B53E515F1CF2041431" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4B96A26AB989A500DFEE5F1CF2049FAF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4B96A26AB989A500DFEE5F1CF2049FAF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_1E2A14A1F36947B53E515F1CF2041431" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4B96A26AB989A500DFEE5F1CF2049FAF" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DynamicSolutionsGroupIncMember" xlink:label="loc_otex_DynamicSolutionsGroupIncMember_87C34FA8A6257F3460655F1CF205A69C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4B96A26AB989A500DFEE5F1CF2049FAF" xlink:to="loc_otex_DynamicSolutionsGroupIncMember_87C34FA8A6257F3460655F1CF205A69C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_22835F95723FC6F9A2105F1CF205FBDA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C39B0175B5B4E41105FE5F1CF205A349" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_22835F95723FC6F9A2105F1CF205FBDA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_60D5ADE1BBE4EC38EB065F1CF20647F8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_C39B0175B5B4E41105FE5F1CF205A349" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_60D5ADE1BBE4EC38EB065F1CF20647F8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfGuidanceSoftwareDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_C7678143CBBFB294CDD6A70C65D14B3C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_C7678143CBBFB294CDD6A70C65D14B3C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_5098C3C054880E37D84DA70C65D1A26B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_C7678143CBBFB294CDD6A70C65D14B3C" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_5098C3C054880E37D84DA70C65D1A26B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E32C46B237327C71C80A70C65D285A5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5098C3C054880E37D84DA70C65D1A26B" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E32C46B237327C71C80A70C65D285A5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E32C46B237327C71C80A70C65D285A5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5098C3C054880E37D84DA70C65D1A26B" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E32C46B237327C71C80A70C65D285A5" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GuidanceSoftwareInc.Member" xlink:label="loc_otex_GuidanceSoftwareInc.Member_ADBD900BDB3D3B9AFAE6A70C65D2E508" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5E32C46B237327C71C80A70C65D285A5" xlink:to="loc_otex_GuidanceSoftwareInc.Member_ADBD900BDB3D3B9AFAE6A70C65D2E508" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_ED51AA6A0B754BFC7C9FA70C65D3DBE7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_C7678143CBBFB294CDD6A70C65D14B3C" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_ED51AA6A0B754BFC7C9FA70C65D3DBE7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_F797E53F98FFB4C140D5A70C65D30484_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_ED51AA6A0B754BFC7C9FA70C65D3DBE7" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_F797E53F98FFB4C140D5A70C65D30484_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_F797E53F98FFB4C140D5A70C65D30484" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_ED51AA6A0B754BFC7C9FA70C65D3DBE7" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_F797E53F98FFB4C140D5A70C65D30484" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerAssetsMember" xlink:label="loc_otex_CustomerAssetsMember_C45D6A614B333F9E9B54A70C65D4837E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_F797E53F98FFB4C140D5A70C65D30484" xlink:to="loc_otex_CustomerAssetsMember_C45D6A614B333F9E9B54A70C65D4837E" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TechnologyAssetsMember" xlink:label="loc_otex_TechnologyAssetsMember_934C16F323CDECCD970DA70C65D40713" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_F797E53F98FFB4C140D5A70C65D30484" xlink:to="loc_otex_TechnologyAssetsMember_934C16F323CDECCD970DA70C65D40713" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_LitigationCaseAxis" xlink:label="loc_srt_LitigationCaseAxis_924C4422C2BD7F4F92B5A70C65D47750" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_C7678143CBBFB294CDD6A70C65D14B3C" xlink:to="loc_srt_LitigationCaseAxis_924C4422C2BD7F4F92B5A70C65D47750" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_LitigationCaseTypeDomain" xlink:label="loc_srt_LitigationCaseTypeDomain_2F2C7CD1C26F9D43F1BBA70C65D4FEE1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_924C4422C2BD7F4F92B5A70C65D47750" xlink:to="loc_srt_LitigationCaseTypeDomain_2F2C7CD1C26F9D43F1BBA70C65D4FEE1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_LitigationCaseTypeDomain" xlink:label="loc_srt_LitigationCaseTypeDomain_2F2C7CD1C26F9D43F1BBA70C65D4FEE1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_924C4422C2BD7F4F92B5A70C65D47750" xlink:to="loc_srt_LitigationCaseTypeDomain_2F2C7CD1C26F9D43F1BBA70C65D4FEE1" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_AppraisalProceedingsMember" xlink:label="loc_otex_AppraisalProceedingsMember_F97B38E70C48D8465B60A70C65D5A7EA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_2F2C7CD1C26F9D43F1BBA70C65D4FEE1" xlink:to="loc_otex_AppraisalProceedingsMember_F97B38E70C48D8465B60A70C65D5A7EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_EE0F4ECBBBEEE8B4B688A70C65D5EA6B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_EE0F4ECBBBEEE8B4B688A70C65D5EA6B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_B389A89E68A17FE20596A70C65D67B65" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_B389A89E68A17FE20596A70C65D67B65" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_B8FB359D053ABFCC50ADA70C65D6C38B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_B389A89E68A17FE20596A70C65D67B65" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_B8FB359D053ABFCC50ADA70C65D6C38B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeFairValue1" xlink:label="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeFairValue1_FCAEB3551A246C2A3A53A70C65D6CD0B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_B389A89E68A17FE20596A70C65D67B65" xlink:to="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeFairValue1_FCAEB3551A246C2A3A53A70C65D6CD0B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyAccrualAtCarryingValue" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_2D91F3406B51D848EE83A70C65D78ACC" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_2D91F3406B51D848EE83A70C65D78ACC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_4E2B27171217EA325601A70C65D7B06A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_4E2B27171217EA325601A70C65D7B06A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets" xlink:label="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_D8CEB2BC7D9FC55A2C6BA70C65D8AB7E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:to="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_D8CEB2BC7D9FC55A2C6BA70C65D8AB7E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_4397780FC8D87FBD7BC1A70C65D8D76F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_4397780FC8D87FBD7BC1A70C65D8D76F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_294D8F938CEC70AC4827A70C65D86882" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_294D8F938CEC70AC4827A70C65D86882" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_2D4C425427E78102385FA70C65D951C0" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_2D4C425427E78102385FA70C65D951C0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_7A1EE0BC45F747D0E63AA70C65D9BB26" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:to="loc_us-gaap_Goodwill_7A1EE0BC45F747D0E63AA70C65D9BB26" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_EEEA91A3F3EE23042788A70C65D9144B" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_EEEA91A3F3EE23042788A70C65D9144B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAcquiredFromAcquisition" xlink:label="loc_us-gaap_CashAcquiredFromAcquisition_9E18EB372A051B7DE976A70C65D944D2" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_7686933DF98427EBA2FAA70C65D734D9" xlink:to="loc_us-gaap_CashAcquiredFromAcquisition_9E18EB372A051B7DE976A70C65D944D2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount" xlink:label="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_63AB284367E27E382F40A70C65DABE1A" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_63AB284367E27E382F40A70C65DABE1A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_611AC53CAA4256A23B54A70C65DAFB01" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_611AC53CAA4256A23B54A70C65DAFB01" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationSeparatelyRecognizedTransactionsAdjustmentDeferredRevenue" xlink:label="loc_otex_BusinessCombinationSeparatelyRecognizedTransactionsAdjustmentDeferredRevenue_217DBAEC515F28239418A75A01A901B5" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_otex_BusinessCombinationSeparatelyRecognizedTransactionsAdjustmentDeferredRevenue_217DBAEC515F28239418A75A01A901B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_CBA084413B7CD4597EFEA70C65DA241E" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_CBA084413B7CD4597EFEA70C65DA241E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_6FAE2EC1D6C48399FB69A70C65DBEC12" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_6FAE2EC1D6C48399FB69A70C65DBEC12" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_164A9D516E378D0F4BE9A70C65DB79E1" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_164A9D516E378D0F4BE9A70C65DB79E1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeRemeasurementGain" xlink:label="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeRemeasurementGain_9B62F7796F277F085964A70C65DB1D7C" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_1F7755CA66644403D6BEA70C65D5B823" xlink:to="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeRemeasurementGain_9B62F7796F277F085964A70C65DB1D7C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfHightailDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1F45E2191636ABC81EF6A70C65F8C590" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1F45E2191636ABC81EF6A70C65F8C590" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_FA77FCDB97DB20E496CDA70C65F87255" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1F45E2191636ABC81EF6A70C65F8C590" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_FA77FCDB97DB20E496CDA70C65F87255" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E1BEC3045A7315C3D2C1A70C65F9818D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FA77FCDB97DB20E496CDA70C65F87255" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E1BEC3045A7315C3D2C1A70C65F9818D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E1BEC3045A7315C3D2C1A70C65F9818D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FA77FCDB97DB20E496CDA70C65F87255" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E1BEC3045A7315C3D2C1A70C65F9818D" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_HightailIncMember" xlink:label="loc_otex_HightailIncMember_0B887D092DE60E7AB69CA70C65F9D549" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E1BEC3045A7315C3D2C1A70C65F9818D" xlink:to="loc_otex_HightailIncMember_0B887D092DE60E7AB69CA70C65F9D549" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GuidanceSoftwareInc.Member" xlink:label="loc_otex_GuidanceSoftwareInc.Member_9126A1B81562098DED8AA70C65FA699C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E1BEC3045A7315C3D2C1A70C65F9818D" xlink:to="loc_otex_GuidanceSoftwareInc.Member_9126A1B81562098DED8AA70C65FA699C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_270C7EB1DDCC36C7B5C8A70C65FAE79A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_270C7EB1DDCC36C7B5C8A70C65FAE79A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_1590D9F36823A0BED8B5A70C65FA8043" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:to="loc_us-gaap_Goodwill_1590D9F36823A0BED8B5A70C65FA8043" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount" xlink:label="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_220339E8A6D421CC8A60A70C65FB5984" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:to="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_220339E8A6D421CC8A60A70C65FB5984" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_8EB36978DE7492DC63EDA70C65FBDFFA" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_8EB36978DE7492DC63EDA70C65FBDFFA" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationSeparatelyRecognizedTransactionsAdjustmentDeferredRevenue" xlink:label="loc_otex_BusinessCombinationSeparatelyRecognizedTransactionsAdjustmentDeferredRevenue_72F4A4D97AB82443D166A7563BE75F4A" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:to="loc_otex_BusinessCombinationSeparatelyRecognizedTransactionsAdjustmentDeferredRevenue_72F4A4D97AB82443D166A7563BE75F4A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_5216546F097ADF19BD9FA70C65FB5125" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_5216546F097ADF19BD9FA70C65FB5125" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_73B05F6090185682DC54A70C65FCDC2C" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_73B05F6090185682DC54A70C65FCDC2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_87172C73F19D27B3879EA70C65FCA8C7" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_2C286EF720B0870F0058A70C65FA992C" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_87172C73F19D27B3879EA70C65FCA8C7" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfHightailPurchasePriceAllocationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_E203160FA7B9171BE8395F1CEDB408C5" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7F400B7739EA858BCA975F1CEDB236C9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E203160FA7B9171BE8395F1CEDB408C5" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7F400B7739EA858BCA975F1CEDB236C9" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9ACEA862118679724A8E5F1CEDB291EB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7F400B7739EA858BCA975F1CEDB236C9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9ACEA862118679724A8E5F1CEDB291EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3611F88125AA3B5389865F1CEDB2EEFE_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9ACEA862118679724A8E5F1CEDB291EB" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3611F88125AA3B5389865F1CEDB2EEFE_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3611F88125AA3B5389865F1CEDB2EEFE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9ACEA862118679724A8E5F1CEDB291EB" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3611F88125AA3B5389865F1CEDB2EEFE" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerAssetsMember" xlink:label="loc_otex_CustomerAssetsMember_57B9D82DAB7F118B15C25F1CEDB352C6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3611F88125AA3B5389865F1CEDB2EEFE" xlink:to="loc_otex_CustomerAssetsMember_57B9D82DAB7F118B15C25F1CEDB352C6" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TechnologyAssetsMember" xlink:label="loc_otex_TechnologyAssetsMember_5D7B6860F4CFEFFCEE905F1CEDB3F12E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3611F88125AA3B5389865F1CEDB2EEFE" xlink:to="loc_otex_TechnologyAssetsMember_5D7B6860F4CFEFFCEE905F1CEDB3F12E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_FC4C7926947D628D99F75F1CEDB3D598" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7F400B7739EA858BCA975F1CEDB236C9" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_FC4C7926947D628D99F75F1CEDB3D598" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_176C9C22F0521BF95D035F1CEDB46A8B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FC4C7926947D628D99F75F1CEDB3D598" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_176C9C22F0521BF95D035F1CEDB46A8B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_176C9C22F0521BF95D035F1CEDB46A8B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_FC4C7926947D628D99F75F1CEDB3D598" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_176C9C22F0521BF95D035F1CEDB46A8B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_HightailIncMember" xlink:label="loc_otex_HightailIncMember_6971E92A5242EE30D6985F1CEDB4819A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_176C9C22F0521BF95D035F1CEDB46A8B" xlink:to="loc_otex_HightailIncMember_6971E92A5242EE30D6985F1CEDB4819A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_9C604CBD0A185AA2AEDA5F1CEDB4BC24" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E203160FA7B9171BE8395F1CEDB408C5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_9C604CBD0A185AA2AEDA5F1CEDB4BC24" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets" xlink:label="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_27D6536868DC3E2344CA5F1CEDB5FF5E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E203160FA7B9171BE8395F1CEDB408C5" xlink:to="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_27D6536868DC3E2344CA5F1CEDB5FF5E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_30B75F3509D9C5A355E55F1CEDB51655" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E203160FA7B9171BE8395F1CEDB408C5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_30B75F3509D9C5A355E55F1CEDB51655" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_52EFC8F22CAAB94E9C145F1CEDB59ABA" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E203160FA7B9171BE8395F1CEDB408C5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_52EFC8F22CAAB94E9C145F1CEDB59ABA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_43E358A971E507E90C0D5F1CEDB54B43" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E203160FA7B9171BE8395F1CEDB408C5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_43E358A971E507E90C0D5F1CEDB54B43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_83508A52A4120FA14B2F5F1CEDB6466C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E203160FA7B9171BE8395F1CEDB408C5" xlink:to="loc_us-gaap_Goodwill_83508A52A4120FA14B2F5F1CEDB6466C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_0FF23FB6376ABF0F93105F1CEDB632CC" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E203160FA7B9171BE8395F1CEDB408C5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_0FF23FB6376ABF0F93105F1CEDB632CC" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfLiaisonTechnologiesIncDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_A14732E90B2F7811B6D15F1CF23D35AB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_12213773C057FB39B3865F1CF23CBE02" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_A14732E90B2F7811B6D15F1CF23D35AB" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_12213773C057FB39B3865F1CF23CBE02" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_4FB10FF5A6C44DE72F705F1CF23C219E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_12213773C057FB39B3865F1CF23CBE02" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_4FB10FF5A6C44DE72F705F1CF23C219E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D855270A71A0675062E05F1CF23CE532_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_4FB10FF5A6C44DE72F705F1CF23C219E" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D855270A71A0675062E05F1CF23CE532_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D855270A71A0675062E05F1CF23CE532" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_4FB10FF5A6C44DE72F705F1CF23C219E" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D855270A71A0675062E05F1CF23CE532" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_LiaisonTechnologiesInc.Member" xlink:label="loc_otex_LiaisonTechnologiesInc.Member_2159A168295E43D633AC5F1CF23D8DCD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D855270A71A0675062E05F1CF23CE532" xlink:to="loc_otex_LiaisonTechnologiesInc.Member_2159A168295E43D633AC5F1CF23D8DCD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_57092705C8230242FA745F1CF23D5E6B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_A14732E90B2F7811B6D15F1CF23D35AB" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_57092705C8230242FA745F1CF23D5E6B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_FE2EB470D4B06D68B12A5F1CF23E689C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_A14732E90B2F7811B6D15F1CF23D35AB" xlink:to="loc_us-gaap_Goodwill_FE2EB470D4B06D68B12A5F1CF23E689C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount" xlink:label="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_D8EB62F430AC19C410C05F1CF23E0341" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_A14732E90B2F7811B6D15F1CF23D35AB" xlink:to="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_D8EB62F430AC19C410C05F1CF23E0341" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_90A7DF6015A67990537F5F1CF23E7150" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_A14732E90B2F7811B6D15F1CF23D35AB" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_90A7DF6015A67990537F5F1CF23E7150" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_B1A3F46FBDBE97A8727D5F1CF23E6010" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_A14732E90B2F7811B6D15F1CF23D35AB" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_B1A3F46FBDBE97A8727D5F1CF23E6010" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_803F1B64D2AD2A67EBE15F1CF23EEB3E" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_A14732E90B2F7811B6D15F1CF23D35AB" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_803F1B64D2AD2A67EBE15F1CF23EEB3E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_435FF353F2E36336572D5F1CF23F4D20" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_A14732E90B2F7811B6D15F1CF23D35AB" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_435FF353F2E36336572D5F1CF23F4D20" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfLiaisonTechnologiesIncPurchasePriceAllocationDetailsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_94D40FD62542A7A95F285F1CF235C6F8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F46D1E764633544BD7B05F1CF22FC34F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_94D40FD62542A7A95F285F1CF235C6F8" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F46D1E764633544BD7B05F1CF22FC34F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_7FE1BE66EC634F705D635F1CF23346D5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F46D1E764633544BD7B05F1CF22FC34F" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_7FE1BE66EC634F705D635F1CF23346D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9AF04C2249950888DA035F1CF23496D3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7FE1BE66EC634F705D635F1CF23346D5" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9AF04C2249950888DA035F1CF23496D3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9AF04C2249950888DA035F1CF23496D3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7FE1BE66EC634F705D635F1CF23346D5" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9AF04C2249950888DA035F1CF23496D3" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_LiaisonTechnologiesInc.Member" xlink:label="loc_otex_LiaisonTechnologiesInc.Member_D9D155AC0E3928926C7F5F1CF23410C7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9AF04C2249950888DA035F1CF23496D3" xlink:to="loc_otex_LiaisonTechnologiesInc.Member_D9D155AC0E3928926C7F5F1CF23410C7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F622BEBCF411E2D2DAE85F1CF2343373" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_F46D1E764633544BD7B05F1CF22FC34F" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F622BEBCF411E2D2DAE85F1CF2343373" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_05D41F9BB62E7A2C00CB5F1CF2348547_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F622BEBCF411E2D2DAE85F1CF2343373" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_05D41F9BB62E7A2C00CB5F1CF2348547_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_05D41F9BB62E7A2C00CB5F1CF2348547" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F622BEBCF411E2D2DAE85F1CF2343373" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_05D41F9BB62E7A2C00CB5F1CF2348547" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerAssetsMember" xlink:label="loc_otex_CustomerAssetsMember_9DFF1D3A9FEBE14421595F1CF235908D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_05D41F9BB62E7A2C00CB5F1CF2348547" xlink:to="loc_otex_CustomerAssetsMember_9DFF1D3A9FEBE14421595F1CF235908D" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TechnologyAssetsMember" xlink:label="loc_otex_TechnologyAssetsMember_EE15B647736FEF3826275F1CF2350C22" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_05D41F9BB62E7A2C00CB5F1CF2348547" xlink:to="loc_otex_TechnologyAssetsMember_EE15B647736FEF3826275F1CF2350C22" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_C59751A904B9228679195F1CF2352BCE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_94D40FD62542A7A95F285F1CF235C6F8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_C59751A904B9228679195F1CF2352BCE" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets" xlink:label="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_6F8A0FD339270199D2DD5F1CF2364EC5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_94D40FD62542A7A95F285F1CF235C6F8" xlink:to="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_6F8A0FD339270199D2DD5F1CF2364EC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_D74C98ED752CA38B87BA5F1CF2361096" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_94D40FD62542A7A95F285F1CF235C6F8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_D74C98ED752CA38B87BA5F1CF2361096" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_1353CA9662EE91E8D4D75F1CF236377D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_94D40FD62542A7A95F285F1CF235C6F8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_1353CA9662EE91E8D4D75F1CF236377D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_F9CDF7DCAB7CD2EB0F185F1CF2365C86" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_94D40FD62542A7A95F285F1CF235C6F8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_F9CDF7DCAB7CD2EB0F185F1CF2365C86" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_2B13AB6BCC257ED0C6265F1CF23626E0" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_94D40FD62542A7A95F285F1CF235C6F8" xlink:to="loc_us-gaap_Goodwill_2B13AB6BCC257ED0C6265F1CF23626E0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_39F11AB6E2BB7B9355235F1CF23715FE" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_94D40FD62542A7A95F285F1CF235C6F8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_39F11AB6E2BB7B9355235F1CF23715FE" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfXmediusDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_AC5CDF39FAC70CB226855F1CF2BC311E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_AC5CDF39FAC70CB226855F1CF2BC311E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_68D7D24E92AA87BAA6075F1CF2BC5A6B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_AC5CDF39FAC70CB226855F1CF2BC311E" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_68D7D24E92AA87BAA6075F1CF2BC5A6B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C9EBEBFEA9542B082B095F1CF2BDCF06_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_68D7D24E92AA87BAA6075F1CF2BC5A6B" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C9EBEBFEA9542B082B095F1CF2BDCF06_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C9EBEBFEA9542B082B095F1CF2BDCF06" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_68D7D24E92AA87BAA6075F1CF2BC5A6B" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C9EBEBFEA9542B082B095F1CF2BDCF06" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_XMediusMember" xlink:label="loc_otex_XMediusMember_F78DAB54E022E22B0D585F1CF2BD8311" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C9EBEBFEA9542B082B095F1CF2BDCF06" xlink:to="loc_otex_XMediusMember_F78DAB54E022E22B0D585F1CF2BD8311" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_E60B3F94593D0529469B5F1CF2BDEA2D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_E60B3F94593D0529469B5F1CF2BDEA2D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_880EA6D5B860FD24171B5F1CF2BE18FF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_us-gaap_Goodwill_880EA6D5B860FD24171B5F1CF2BE18FF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount" xlink:label="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_164F8D2222FAF607E43E5F1CF2BE77FF" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_164F8D2222FAF607E43E5F1CF2BE77FF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_B0027961D38DD98262925F1CF2BE75BC" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_B0027961D38DD98262925F1CF2BE75BC" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredRevenue" xlink:label="loc_otex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredRevenue_55814FD77A6B2A7EBF4F5F1CF2BE67B4" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_otex_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredRevenue_55814FD77A6B2A7EBF4F5F1CF2BE67B4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_2B6036689BE0A53B9DF35F1CF2BF33AF" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_2B6036689BE0A53B9DF35F1CF2BF33AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_CFC32BE0B1C7E6348A925F1CF2BFB219" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_CFC32BE0B1C7E6348A925F1CF2BFB219" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_539DE7FF6241BD1548E95F1CF2BFF45F" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_539DE7FF6241BD1548E95F1CF2BFF45F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_298FCAA30EF433372C405F1CF2BF7462" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_233598AACB576A60F4675F1CF2BDA9CF" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_298FCAA30EF433372C405F1CF2BF7462" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAcquisitionOfXmediusPreliminaryPurchasePriceAllocationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_D79817F3BA93C78C4B365F1CF108DE60" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7EFD7B6E246A0D2FC3FF5F1CF106BCF0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D79817F3BA93C78C4B365F1CF108DE60" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7EFD7B6E246A0D2FC3FF5F1CF106BCF0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_D8EF4925693D1EE7B6AD5F1CF106F935" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7EFD7B6E246A0D2FC3FF5F1CF106BCF0" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_D8EF4925693D1EE7B6AD5F1CF106F935" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C056E65C268ED5EE830B5F1CF10768D8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_D8EF4925693D1EE7B6AD5F1CF106F935" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C056E65C268ED5EE830B5F1CF10768D8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C056E65C268ED5EE830B5F1CF10768D8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_D8EF4925693D1EE7B6AD5F1CF106F935" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C056E65C268ED5EE830B5F1CF10768D8" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_XMediusMember" xlink:label="loc_otex_XMediusMember_7425C5335F8E7009F36D5F1CF1076F45" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_C056E65C268ED5EE830B5F1CF10768D8" xlink:to="loc_otex_XMediusMember_7425C5335F8E7009F36D5F1CF1076F45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9C34B9B66D007ED5E0EB5F1CF10863F9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_7EFD7B6E246A0D2FC3FF5F1CF106BCF0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9C34B9B66D007ED5E0EB5F1CF10863F9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0510D9DCF917699F0B795F1CF108F406_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9C34B9B66D007ED5E0EB5F1CF10863F9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0510D9DCF917699F0B795F1CF108F406_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0510D9DCF917699F0B795F1CF108F406" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9C34B9B66D007ED5E0EB5F1CF10863F9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0510D9DCF917699F0B795F1CF108F406" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerAssetsMember" xlink:label="loc_otex_CustomerAssetsMember_31555904E7BDA1BFC2285F1CF10801B1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0510D9DCF917699F0B795F1CF108F406" xlink:to="loc_otex_CustomerAssetsMember_31555904E7BDA1BFC2285F1CF10801B1" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TechnologyAssetsMember" xlink:label="loc_otex_TechnologyAssetsMember_009A364F10D0E2939F365F1CF1081041" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0510D9DCF917699F0B795F1CF108F406" xlink:to="loc_otex_TechnologyAssetsMember_009A364F10D0E2939F365F1CF1081041" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_9DD9FE5AB8D128B880EB5F1CF109F2E8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D79817F3BA93C78C4B365F1CF108DE60" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_9DD9FE5AB8D128B880EB5F1CF109F2E8" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets" xlink:label="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_AF68420CAD5A705BE3475F1CF1091A7F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D79817F3BA93C78C4B365F1CF108DE60" xlink:to="loc_otex_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedNoncurrentTangibleAssets_AF68420CAD5A705BE3475F1CF1091A7F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_47D2AF5BCCC3A48BF5735F1CF1091F6C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D79817F3BA93C78C4B365F1CF108DE60" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_47D2AF5BCCC3A48BF5735F1CF1091F6C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_F7A9C29D5EE0CC5DE1235F1CF10AB658" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D79817F3BA93C78C4B365F1CF108DE60" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_F7A9C29D5EE0CC5DE1235F1CF10AB658" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_41012A2F2788A25CD8095F1CF10A4650" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D79817F3BA93C78C4B365F1CF108DE60" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_41012A2F2788A25CD8095F1CF10A4650" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_AEF8B8A0852863AA8EB45F1CF10A934A" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D79817F3BA93C78C4B365F1CF108DE60" xlink:to="loc_us-gaap_Goodwill_AEF8B8A0852863AA8EB45F1CF10A934A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_1C342944DD726C15BA565F1CF10A3323" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D79817F3BA93C78C4B365F1CF108DE60" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_1C342944DD726C15BA565F1CF10A3323" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsAppraisalProceedingsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_B5C26F55330964DE3FD25F1CEDA05C9D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_051AC72FC6BF8B7313415F1CED9DBEDB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B5C26F55330964DE3FD25F1CEDA05C9D" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_051AC72FC6BF8B7313415F1CED9DBEDB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_LitigationCaseAxis" xlink:label="loc_srt_LitigationCaseAxis_F2981042B0D5C2CCC1C85F1CED9E02C2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_051AC72FC6BF8B7313415F1CED9DBEDB" xlink:to="loc_srt_LitigationCaseAxis_F2981042B0D5C2CCC1C85F1CED9E02C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_LitigationCaseTypeDomain" xlink:label="loc_srt_LitigationCaseTypeDomain_7B40F0B1C10182B2A0CE5F1CED9E5310_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_F2981042B0D5C2CCC1C85F1CED9E02C2" xlink:to="loc_srt_LitigationCaseTypeDomain_7B40F0B1C10182B2A0CE5F1CED9E5310_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_LitigationCaseTypeDomain" xlink:label="loc_srt_LitigationCaseTypeDomain_7B40F0B1C10182B2A0CE5F1CED9E5310" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_F2981042B0D5C2CCC1C85F1CED9E02C2" xlink:to="loc_srt_LitigationCaseTypeDomain_7B40F0B1C10182B2A0CE5F1CED9E5310" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_AppraisalProceedingsMember" xlink:label="loc_otex_AppraisalProceedingsMember_5E5FAB4028CDF86E70885F1CED9F0E0D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_7B40F0B1C10182B2A0CE5F1CED9E5310" xlink:to="loc_otex_AppraisalProceedingsMember_5E5FAB4028CDF86E70885F1CED9F0E0D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_BFDF1B0BDD509F979F0D5F1CED9F0ADD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_051AC72FC6BF8B7313415F1CED9DBEDB" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_BFDF1B0BDD509F979F0D5F1CED9F0ADD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_859D4DC04B8DF9B1B8855F1CED9F71D7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BFDF1B0BDD509F979F0D5F1CED9F0ADD" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_859D4DC04B8DF9B1B8855F1CED9F71D7_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_859D4DC04B8DF9B1B8855F1CED9F71D7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BFDF1B0BDD509F979F0D5F1CED9F0ADD" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_859D4DC04B8DF9B1B8855F1CED9F71D7" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GuidanceSoftwareInc.Member" xlink:label="loc_otex_GuidanceSoftwareInc.Member_BFE40DCE4C154B7F50395F1CED9F76FD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_859D4DC04B8DF9B1B8855F1CED9F71D7" xlink:to="loc_otex_GuidanceSoftwareInc.Member_BFE40DCE4C154B7F50395F1CED9F76FD" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_LossContingencyIssuedandOutstandingSharesatAcquisition" xlink:label="loc_otex_LossContingencyIssuedandOutstandingSharesatAcquisition_20D540F00917DB8540285F1CEDA0BDAF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B5C26F55330964DE3FD25F1CEDA05C9D" xlink:to="loc_otex_LossContingencyIssuedandOutstandingSharesatAcquisition_20D540F00917DB8540285F1CEDA0BDAF" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_LossContingencyPercentofSharesOutstanding" xlink:label="loc_otex_LossContingencyPercentofSharesOutstanding_AF04F35D65306FAE5C715F1CEDA08666" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B5C26F55330964DE3FD25F1CEDA05C9D" xlink:to="loc_otex_LossContingencyPercentofSharesOutstanding_AF04F35D65306FAE5C715F1CEDA08666" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyAccrualAtCarryingValue" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_30E29B43CDF3450F27E75F1CEDA0919A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B5C26F55330964DE3FD25F1CEDA05C9D" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_30E29B43CDF3450F27E75F1CEDA0919A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionSharePrice" xlink:label="loc_us-gaap_BusinessAcquisitionSharePrice_1BCA7237272BC7E0841F5F1CEDA19F12" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B5C26F55330964DE3FD25F1CEDA05C9D" xlink:to="loc_us-gaap_BusinessAcquisitionSharePrice_1BCA7237272BC7E0841F5F1CEDA19F12" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForLegalSettlements" xlink:label="loc_us-gaap_PaymentsForLegalSettlements_6EAB52BE9C659A6CD3C95F1CEDA17B3D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B5C26F55330964DE3FD25F1CEDA05C9D" xlink:to="loc_us-gaap_PaymentsForLegalSettlements_6EAB52BE9C659A6CD3C95F1CEDA17B3D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AcquisitionsTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_F8603EBA55D47545E0065F1CF0AFFA9A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_353890BD0906D77D79555F1CF0AD9B98" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F8603EBA55D47545E0065F1CF0AFFA9A" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_353890BD0906D77D79555F1CF0AD9B98" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_DBB1222E7D8231C785455F1CF0AD5BEF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_353890BD0906D77D79555F1CF0AD9B98" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_DBB1222E7D8231C785455F1CF0AD5BEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_DBB1222E7D8231C785455F1CF0AD5BEF" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_DBB1222E7D8231C785455F1CF0AD5BEF" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_XMediusMember" xlink:label="loc_otex_XMediusMember_9861EB34E6E3B47434A75F1CF0AE5238" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB" xlink:to="loc_otex_XMediusMember_9861EB34E6E3B47434A75F1CF0AE5238" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CarboniteInc.Member" xlink:label="loc_otex_CarboniteInc.Member_BCCF54602A405809974A5F1CF0AEAF92" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB" xlink:to="loc_otex_CarboniteInc.Member_BCCF54602A405809974A5F1CF0AEAF92" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CatalystRepositorySystemsIncMember" xlink:label="loc_otex_CatalystRepositorySystemsIncMember_437B383C9BE6FCC889EE5F1CF0AE45F2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB" xlink:to="loc_otex_CatalystRepositorySystemsIncMember_437B383C9BE6FCC889EE5F1CF0AE45F2" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_LiaisonTechnologiesInc.Member" xlink:label="loc_otex_LiaisonTechnologiesInc.Member_F948999A5EB1DDA499A05F1CF0AE9C4F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB" xlink:to="loc_otex_LiaisonTechnologiesInc.Member_F948999A5EB1DDA499A05F1CF0AE9C4F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_HightailIncMember" xlink:label="loc_otex_HightailIncMember_2CA4FCBBC7B3D38448A25F1CF0AF4227" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB" xlink:to="loc_otex_HightailIncMember_2CA4FCBBC7B3D38448A25F1CF0AF4227" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GuidanceSoftwareInc.Member" xlink:label="loc_otex_GuidanceSoftwareInc.Member_EC44CA98DFBCA12695315F1CF0AFF450" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB" xlink:to="loc_otex_GuidanceSoftwareInc.Member_EC44CA98DFBCA12695315F1CF0AFF450" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CovisintCorporationMember" xlink:label="loc_otex_CovisintCorporationMember_E6756CD5CAF996463F405F1CF0AFE961" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_33388CE0902CB26151435F1CF0AD59FB" xlink:to="loc_otex_CovisintCorporationMember_E6756CD5CAF996463F405F1CF0AFE961" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_EC1DCC35FC0529D4A8835F1CF0B01B00" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F8603EBA55D47545E0065F1CF0AFFA9A" xlink:to="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_EC1DCC35FC0529D4A8835F1CF0B01B00" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationTextBlock_9D807D3CA37E06E0766C5F1CF0B058C9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F8603EBA55D47545E0065F1CF0AFFA9A" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaInformationTextBlock_9D807D3CA37E06E0766C5F1CF0B058C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock_6670B7251A57D30F55BC5F1CF0B017C9" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_F8603EBA55D47545E0065F1CF0AFFA9A" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock_6670B7251A57D30F55BC5F1CF0B017C9" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/AllowanceForDoubtfulAccounts" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AllowanceForDoubtfulAccountsChangesInCarryingAmountDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/AllowanceForDoubtfulAccountsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/BasisOfPresentation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/BasisOfPresentationAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MinorityInterestLineItems" xlink:label="loc_us-gaap_MinorityInterestLineItems_FF3457ACD8C9DB5768195F1CF35B76AB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MinorityInterestTable" xlink:label="loc_us-gaap_MinorityInterestTable_C4B7DF0CC280A30854755F1CF35A2ABB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MinorityInterestLineItems_FF3457ACD8C9DB5768195F1CF35B76AB" xlink:to="loc_us-gaap_MinorityInterestTable_C4B7DF0CC280A30854755F1CF35A2ABB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_OwnershipAxis" xlink:label="loc_srt_OwnershipAxis_C43D1C8D49D44FBA7F835F1CF35AD7CC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_C4B7DF0CC280A30854755F1CF35A2ABB" xlink:to="loc_srt_OwnershipAxis_C43D1C8D49D44FBA7F835F1CF35AD7CC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_OwnershipDomain" xlink:label="loc_srt_OwnershipDomain_6DB9EBF610B9950A084F5F1CF35B9BE2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_C43D1C8D49D44FBA7F835F1CF35AD7CC" xlink:to="loc_srt_OwnershipDomain_6DB9EBF610B9950A084F5F1CF35B9BE2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_OwnershipDomain" xlink:label="loc_srt_OwnershipDomain_6DB9EBF610B9950A084F5F1CF35B9BE2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_C43D1C8D49D44FBA7F835F1CF35AD7CC" xlink:to="loc_srt_OwnershipDomain_6DB9EBF610B9950A084F5F1CF35B9BE2" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_OpenTextSouthAfricaProprietaryLtdMember" xlink:label="loc_otex_OpenTextSouthAfricaProprietaryLtdMember_E80F68BFF1D24E2C0D805F1CF35B5D26" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_6DB9EBF610B9950A084F5F1CF35B9BE2" xlink:to="loc_otex_OpenTextSouthAfricaProprietaryLtdMember_E80F68BFF1D24E2C0D805F1CF35B5D26" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EC1Pte.LtdMember" xlink:label="loc_otex_EC1Pte.LtdMember_0F8CCBA8A006A05F4E5A5F1CF35BC62D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_6DB9EBF610B9950A084F5F1CF35B9BE2" xlink:to="loc_otex_EC1Pte.LtdMember_0F8CCBA8A006A05F4E5A5F1CF35BC62D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_ABB6391812F235DF7B775F1CF35CA9BE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_FF3457ACD8C9DB5768195F1CF35B76AB" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_ABB6391812F235DF7B775F1CF35CA9BE" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/BasisOfPresentationLeaseDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB9BC5DECB5FF072E63481FD67CBFE5C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_080DC6A31C12B464D96C81FD67CA2D30" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB9BC5DECB5FF072E63481FD67CBFE5C" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_080DC6A31C12B464D96C81FD67CA2D30" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_76581B9020F37B24D4268208B1802B57" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_080DC6A31C12B464D96C81FD67CA2D30" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_76581B9020F37B24D4268208B1802B57" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_99A0A14420F03B7B3CB38208B1868860_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_76581B9020F37B24D4268208B1802B57" xlink:to="loc_us-gaap_TypeOfAdoptionMember_99A0A14420F03B7B3CB38208B1868860_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_99A0A14420F03B7B3CB38208B1868860" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_76581B9020F37B24D4268208B1802B57" xlink:to="loc_us-gaap_TypeOfAdoptionMember_99A0A14420F03B7B3CB38208B1868860" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountingStandardsUpdate201602Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201602Member_B3BBABE3B3033C7078D98208F8D2B6F4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_99A0A14420F03B7B3CB38208B1868860" xlink:to="loc_us-gaap_AccountingStandardsUpdate201602Member_B3BBABE3B3033C7078D98208F8D2B6F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountingStandardsUpdateExtensibleList" xlink:label="loc_us-gaap_AccountingStandardsUpdateExtensibleList_1D963643567A3E0A068A81FD67CCB7A1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB9BC5DECB5FF072E63481FD67CBFE5C" xlink:to="loc_us-gaap_AccountingStandardsUpdateExtensibleList_1D963643567A3E0A068A81FD67CCB7A1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_08F7C47BFEBC7B7BF21F81FD67CC095F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB9BC5DECB5FF072E63481FD67CBFE5C" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_08F7C47BFEBC7B7BF21F81FD67CC095F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:label="loc_us-gaap_OperatingLeaseLiability_77E9B59C97BDB99845B081FD67CCFE96" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB9BC5DECB5FF072E63481FD67CBFE5C" xlink:to="loc_us-gaap_OperatingLeaseLiability_77E9B59C97BDB99845B081FD67CCFE96" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_6DD431578C607440F63481FD67CC59D0" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB9BC5DECB5FF072E63481FD67CBFE5C" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_6DD431578C607440F63481FD67CC59D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_9B702B2D0DC79E149B3881FD67CCA1C3" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB9BC5DECB5FF072E63481FD67CBFE5C" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_9B702B2D0DC79E149B3881FD67CCA1C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccruedLiabilitiesCurrentAndNoncurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_4225BC9CF73C7D2C0B7281FD67CDA902" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB9BC5DECB5FF072E63481FD67CBFE5C" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrentAndNoncurrent_4225BC9CF73C7D2C0B7281FD67CDA902" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ConsolidatedBalanceSheets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_3D6857C3F39997F68A3BBF8560DFEA56" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_13251B4AE12189A1A3F2BF8560DD7584" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_3D6857C3F39997F68A3BBF8560DFEA56" xlink:to="loc_us-gaap_StatementTable_13251B4AE12189A1A3F2BF8560DD7584" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_078CD4BBE797AD36165BBF8560DD7D70" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_13251B4AE12189A1A3F2BF8560DD7584" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_078CD4BBE797AD36165BBF8560DD7D70" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_078CD4BBE797AD36165BBF8560DD7D70" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_078CD4BBE797AD36165BBF8560DD7D70" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_XMediusMember" xlink:label="loc_otex_XMediusMember_7A82AE6F7DA179E0CFC1BF8560DE9A94" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:to="loc_otex_XMediusMember_7A82AE6F7DA179E0CFC1BF8560DE9A94" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CarboniteInc.Member" xlink:label="loc_otex_CarboniteInc.Member_702E25284A49B9FA7C86BF8560DEA739" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:to="loc_otex_CarboniteInc.Member_702E25284A49B9FA7C86BF8560DEA739" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DynamicSolutionsGroupIncMember" xlink:label="loc_otex_DynamicSolutionsGroupIncMember_FE894A2EDBF307101351BF8560DE0CD0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:to="loc_otex_DynamicSolutionsGroupIncMember_FE894A2EDBF307101351BF8560DE0CD0" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CatalystRepositorySystemsIncMember" xlink:label="loc_otex_CatalystRepositorySystemsIncMember_09EC7147AF1A2E5F9345BF8560DE9098" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:to="loc_otex_CatalystRepositorySystemsIncMember_09EC7147AF1A2E5F9345BF8560DE9098" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_LiaisonTechnologiesInc.Member" xlink:label="loc_otex_LiaisonTechnologiesInc.Member_A6104A5FE5D47F618699BF8560DFD058" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:to="loc_otex_LiaisonTechnologiesInc.Member_A6104A5FE5D47F618699BF8560DFD058" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_HightailIncMember" xlink:label="loc_otex_HightailIncMember_42963856308D306FFC6FBF8560DF93A2" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:to="loc_otex_HightailIncMember_42963856308D306FFC6FBF8560DF93A2" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GuidanceSoftwareInc.Member" xlink:label="loc_otex_GuidanceSoftwareInc.Member_E056817056E44E5FB4DCBF8560DFF82A" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:to="loc_otex_GuidanceSoftwareInc.Member_E056817056E44E5FB4DCBF8560DFF82A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CovisintCorporationMember" xlink:label="loc_otex_CovisintCorporationMember_CCF2182761BDE673FCA5BF8560DF1993" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC2312821441ABD57707BF8560DD130B" xlink:to="loc_otex_CovisintCorporationMember_CCF2182761BDE673FCA5BF8560DF1993" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_1B0358AD566D21065C93BF8560DF4BB3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3D6857C3F39997F68A3BBF8560DFEA56" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_1B0358AD566D21065C93BF8560DF4BB3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_4E374BFEA40271E38AF2BF8560E07B82" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_1B0358AD566D21065C93BF8560DF4BB3" xlink:to="loc_us-gaap_ProfitLoss_4E374BFEA40271E38AF2BF8560E07B82" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_1B0358AD566D21065C93BF8560DF4BB3" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherDepreciationAndAmortization" xlink:label="loc_us-gaap_OtherDepreciationAndAmortization_E16B727CA9FE119D14E4BF8560E5AF71" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_OtherDepreciationAndAmortization_E16B727CA9FE119D14E4BF8560E5AF71" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_6F3477CF849947B26A56BF8560E6AF6D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_ShareBasedCompensation_6F3477CF849947B26A56BF8560E6AF6D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionExpense" xlink:label="loc_us-gaap_PensionExpense_27D6471F02B9B1BF7AF4BF8560E60916" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_PensionExpense_27D6471F02B9B1BF7AF4BF8560E60916" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfFinancingCosts" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_173C40CC4977F611D2FDBF8560E682FB" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_173C40CC4977F611D2FDBF8560E682FB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAmortizationOfDeferredCharges" xlink:label="loc_us-gaap_OtherAmortizationOfDeferredCharges_625D54E6441EBE70DA8CBF8560E63E9C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_OtherAmortizationOfDeferredCharges_625D54E6441EBE70DA8CBF8560E63E9C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_5D7DC1BF5D969C89ABE1BF8560E6F86C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_5D7DC1BF5D969C89ABE1BF8560E6F86C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost_093ACFB02439AE694DE7BF8560E72620" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost_093ACFB02439AE694DE7BF8560E72620" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_2ECEF28B8E6BC8E0C185BF8560E73D24" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_2ECEF28B8E6BC8E0C185BF8560E73D24" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments" xlink:label="loc_us-gaap_MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments_006DF0B3BA70C8DC078ABF8560E77059" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments_006DF0B3BA70C8DC078ABF8560E77059" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_796F557A69F2D7DEEB40BF8560E77FEC" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_796F557A69F2D7DEEB40BF8560E77FEC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_FC116C4D2FE6AD495ABFBF8560E81F3C" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_FC116C4D2FE6AD495ABFBF8560E81F3C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_C0E1EB72C313A38D09E6BF8560E81E61" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_BEACBAC9D727D9AA7DF7BF8560E522BF" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_C0E1EB72C313A38D09E6BF8560E81E61" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_1B0358AD566D21065C93BF8560DF4BB3" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInReceivables" xlink:label="loc_us-gaap_IncreaseDecreaseInReceivables_630134C6D42A2A982956BF8560E83B30" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:to="loc_us-gaap_IncreaseDecreaseInReceivables_630134C6D42A2A982956BF8560E83B30" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerAsset" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerAsset_619A07A55689B61B04D1BF8560E90889" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerAsset_619A07A55689B61B04D1BF8560E90889" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_430120E269AF2D07FF1EBF8560E96731" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_430120E269AF2D07FF1EBF8560E96731" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInIncomeTaxes" xlink:label="loc_us-gaap_IncreaseDecreaseInIncomeTaxes_6A2405CF9B23044D2338BF8560E9B285" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:to="loc_us-gaap_IncreaseDecreaseInIncomeTaxes_6A2405CF9B23044D2338BF8560E9B285" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_A57DF534A7A02D22CD5ABF8560E9B0E5" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_A57DF534A7A02D22CD5ABF8560E9B0E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_4C047FF565A5A0CD142ABF8560E9A53E" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_4C047FF565A5A0CD142ABF8560E9A53E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_C8A90A8FA5288DBBE0F6BF8560EA28F3" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_C8A90A8FA5288DBBE0F6BF8560EA28F3" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_IncreaseDecreaseinOperatingLeaseAssetsandLiabilitiesNet" xlink:label="loc_otex_IncreaseDecreaseinOperatingLeaseAssetsandLiabilitiesNet_895AC8C5E278C1EFC578BF8560EAD967" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_40CEC95807FB41DE5E3CBF8560E8D2A4" xlink:to="loc_otex_IncreaseDecreaseinOperatingLeaseAssetsandLiabilitiesNet_895AC8C5E278C1EFC578BF8560EAD967" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_D1B49624C57E87297473BF8560EADB44" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_1B0358AD566D21065C93BF8560DF4BB3" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_D1B49624C57E87297473BF8560EADB44" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0452FB81C926A1A55DECBF8560EACEE5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3D6857C3F39997F68A3BBF8560DFEA56" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0452FB81C926A1A55DECBF8560EACEE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireProductiveAssets" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_2AF25C15B174074D7C97BF8560EA256D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0452FB81C926A1A55DECBF8560EACEE5" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_2AF25C15B174074D7C97BF8560EA256D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_F086DF25D52B7FFAFF31BF8560EBB36A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0452FB81C926A1A55DECBF8560EACEE5" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_F086DF25D52B7FFAFF31BF8560EBB36A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_F4BFC391F280D9D4FA18BF8560EB0CBB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0452FB81C926A1A55DECBF8560EACEE5" xlink:to="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_F4BFC391F280D9D4FA18BF8560EB0CBB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_4992872ACEDF8522C16CBF8560EB4070" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_0452FB81C926A1A55DECBF8560EACEE5" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_4992872ACEDF8522C16CBF8560EB4070" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3D6857C3F39997F68A3BBF8560DFEA56" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_BB02CC84DC065F69D43CBF8560EB0BB9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_BB02CC84DC065F69D43CBF8560EB0BB9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_389AFFFDEEC8C8E67B4FBF8560EC227E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_389AFFFDEEC8C8E67B4FBF8560EC227E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RepaymentsOfLongTermDebt" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_FEB0DC2278561B6723B7BF8560ECF9B8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_FEB0DC2278561B6723B7BF8560ECF9B8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsOfDebtExtinguishmentCosts" xlink:label="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_C013C091DEA8AF110093BF8560EC20A4" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:to="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_C013C091DEA8AF110093BF8560EC20A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_9000E038CB8A1A26827CBF8560ECC48D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_9000E038CB8A1A26827CBF8560ECC48D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_CB3FD28DF3C1978F7BE2BF8560ED2384" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_CB3FD28DF3C1978F7BE2BF8560ED2384" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToMinorityShareholders" xlink:label="loc_us-gaap_PaymentsToMinorityShareholders_158AD0CCA35D84FF9A9ABF8560ED7EAD" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:to="loc_us-gaap_PaymentsToMinorityShareholders_158AD0CCA35D84FF9A9ABF8560ED7EAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsOfDividends" xlink:label="loc_us-gaap_PaymentsOfDividends_611BAE8F8D3B04ECC854BF8560EDAA0A" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:to="loc_us-gaap_PaymentsOfDividends_611BAE8F8D3B04ECC854BF8560EDAA0A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_B52431C331206D408BADBF8560EDC378" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_D8DBE6692D5EABF71B00BF8560EB6444" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_B52431C331206D408BADBF8560EDC378" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_E6BC5131CE9B1D08FC93BF8560ED5150" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3D6857C3F39997F68A3BBF8560DFEA56" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_E6BC5131CE9B1D08FC93BF8560ED5150" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_7808592C30A4415270ECBF8560EECCE5" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3D6857C3F39997F68A3BBF8560DFEA56" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_7808592C30A4415270ECBF8560EECCE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_82F197F6A67D3DEFD27BBF8560EEE7C9" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3D6857C3F39997F68A3BBF8560DFEA56" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_82F197F6A67D3DEFD27BBF8560EEE7C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_2B588B8B081959929FDEBF8560EE0334" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_3D6857C3F39997F68A3BBF8560DFEA56" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_2B588B8B081959929FDEBF8560EE0334" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_0DBF06116830524E1D6ABF8560EEBC94" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_2B588B8B081959929FDEBF8560EE0334" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_0DBF06116830524E1D6ABF8560EEBC94" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedCash" xlink:label="loc_us-gaap_RestrictedCash_DD714134F020CFE05E01BF8560EF92B5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_2B588B8B081959929FDEBF8560EE0334" xlink:to="loc_us-gaap_RestrictedCash_DD714134F020CFE05E01BF8560EF92B5" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/ConsolidatedStatementsOfComprehensiveIncomeParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/ConsolidatedStatementsOfIncome" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_03D7F989B373E394AC3F81FD1D58D0AD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_EACC0169F1932746D4E281FD1D51ED24" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_03D7F989B373E394AC3F81FD1D58D0AD" xlink:to="loc_us-gaap_StatementTable_EACC0169F1932746D4E281FD1D51ED24" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_6B133EF123AAECBD943C81FD1D532EBD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_EACC0169F1932746D4E281FD1D51ED24" xlink:to="loc_srt_ProductOrServiceAxis_6B133EF123AAECBD943C81FD1D532EBD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_C4634BFADF31524AF0CF81FD1D53D82D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_6B133EF123AAECBD943C81FD1D532EBD" xlink:to="loc_srt_ProductsAndServicesDomain_C4634BFADF31524AF0CF81FD1D53D82D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_C4634BFADF31524AF0CF81FD1D53D82D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_6B133EF123AAECBD943C81FD1D532EBD" xlink:to="loc_srt_ProductsAndServicesDomain_C4634BFADF31524AF0CF81FD1D53D82D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LicenseMember" xlink:label="loc_us-gaap_LicenseMember_E9B7D14B49223ED25CFE81FD1D53ECAB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_C4634BFADF31524AF0CF81FD1D53D82D" xlink:to="loc_us-gaap_LicenseMember_E9B7D14B49223ED25CFE81FD1D53ECAB" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CloudServicesAndSubscriptionsMember" xlink:label="loc_otex_CloudServicesAndSubscriptionsMember_6119A4BAE3928A5DF08881FD1D572864" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_C4634BFADF31524AF0CF81FD1D53D82D" xlink:to="loc_otex_CloudServicesAndSubscriptionsMember_6119A4BAE3928A5DF08881FD1D572864" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerSupportMember" xlink:label="loc_otex_CustomerSupportMember_4CBED25084718202C4F781FD1D57DE20" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_C4634BFADF31524AF0CF81FD1D53D82D" xlink:to="loc_otex_CustomerSupportMember_4CBED25084718202C4F781FD1D57DE20" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ProfessionalServiceAndOtherMember" xlink:label="loc_otex_ProfessionalServiceAndOtherMember_B6E3EE03010796D9677B81FD1D581944" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_C4634BFADF31524AF0CF81FD1D53D82D" xlink:to="loc_otex_ProfessionalServiceAndOtherMember_B6E3EE03010796D9677B81FD1D581944" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="loc_us-gaap_RevenuesAbstract_AAA327CEFF5733E1CEB681FD1D58A211" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_03D7F989B373E394AC3F81FD1D58D0AD" xlink:to="loc_us-gaap_RevenuesAbstract_AAA327CEFF5733E1CEB681FD1D58A211" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_E2516D583528EE9566C481FD1D58AE07" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_AAA327CEFF5733E1CEB681FD1D58A211" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_E2516D583528EE9566C481FD1D58AE07" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfRevenueAbstract" xlink:label="loc_us-gaap_CostOfRevenueAbstract_925504F68E4D6D97E10181FD1D595E50" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_03D7F989B373E394AC3F81FD1D58D0AD" xlink:to="loc_us-gaap_CostOfRevenueAbstract_925504F68E4D6D97E10181FD1D595E50" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization_3C730141D008944319DE81FD1D59EEEF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_925504F68E4D6D97E10181FD1D595E50" xlink:to="loc_us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization_3C730141D008944319DE81FD1D59EEEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_1A2810F57384B44C7D9881FD1D59974B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_925504F68E4D6D97E10181FD1D595E50" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_1A2810F57384B44C7D9881FD1D59974B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_BF4DDDB0CDCB23C6C68F81FD1D590337" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_925504F68E4D6D97E10181FD1D595E50" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_BF4DDDB0CDCB23C6C68F81FD1D590337" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ConsolidatedStatementsOfShareholdersEquity" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_519E84CAEADF2EBCAD3EA70C4673917C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_6FC754B021D900382EB4A70C45F98C07" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_519E84CAEADF2EBCAD3EA70C4673917C" xlink:to="loc_us-gaap_StatementTable_6FC754B021D900382EB4A70C45F98C07" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_A2FCEE50C2500CD03560A70C45FA5012" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_6FC754B021D900382EB4A70C45F98C07" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_A2FCEE50C2500CD03560A70C45FA5012" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_05B5B206F0E8D2627984A70C45FAABDC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_A2FCEE50C2500CD03560A70C45FA5012" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_05B5B206F0E8D2627984A70C45FAABDC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_05B5B206F0E8D2627984A70C45FAABDC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_A2FCEE50C2500CD03560A70C45FA5012" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_05B5B206F0E8D2627984A70C45FAABDC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_A96131B494CFC7AD43ECA70C45FAD37A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_05B5B206F0E8D2627984A70C45FAABDC" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_A96131B494CFC7AD43ECA70C45FAD37A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_1E279098EFB926946493A70C45FC82E8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_6FC754B021D900382EB4A70C45F98C07" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_1E279098EFB926946493A70C45FC82E8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_9A3FFDC08ED2BCEBCA0DA70C45FC8A28_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_1E279098EFB926946493A70C45FC82E8" xlink:to="loc_us-gaap_EquityComponentDomain_9A3FFDC08ED2BCEBCA0DA70C45FC8A28_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_9A3FFDC08ED2BCEBCA0DA70C45FC8A28" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_1E279098EFB926946493A70C45FC82E8" xlink:to="loc_us-gaap_EquityComponentDomain_9A3FFDC08ED2BCEBCA0DA70C45FC8A28" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember_5E50AE01883F3F061CF4A70C45FC6711" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9A3FFDC08ED2BCEBCA0DA70C45FC8A28" xlink:to="loc_us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember_5E50AE01883F3F061CF4A70C45FC6711" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockMember" xlink:label="loc_us-gaap_TreasuryStockMember_ADCAC6522D8480A26BE5A70C460170AF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9A3FFDC08ED2BCEBCA0DA70C45FC8A28" xlink:to="loc_us-gaap_TreasuryStockMember_ADCAC6522D8480A26BE5A70C460170AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_148B18D53856200F8D42A70C4602C11A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9A3FFDC08ED2BCEBCA0DA70C45FC8A28" xlink:to="loc_us-gaap_RetainedEarningsMember_148B18D53856200F8D42A70C4602C11A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_A857FA8EC53A439B64DBA70C4602F29F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9A3FFDC08ED2BCEBCA0DA70C45FC8A28" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_A857FA8EC53A439B64DBA70C4602F29F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncontrollingInterestMember" xlink:label="loc_us-gaap_NoncontrollingInterestMember_72CD2F5CC3CC11959332A70C46025398" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9A3FFDC08ED2BCEBCA0DA70C45FC8A28" xlink:to="loc_us-gaap_NoncontrollingInterestMember_72CD2F5CC3CC11959332A70C46025398" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_A5D66E6BE81D51D33A43A70C46031FFD" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_6FC754B021D900382EB4A70C45F98C07" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_A5D66E6BE81D51D33A43A70C46031FFD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_E62DBBAB877276B92642A70C4603A430_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_A5D66E6BE81D51D33A43A70C46031FFD" xlink:to="loc_us-gaap_TypeOfAdoptionMember_E62DBBAB877276B92642A70C4603A430_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_E62DBBAB877276B92642A70C4603A430" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_A5D66E6BE81D51D33A43A70C46031FFD" xlink:to="loc_us-gaap_TypeOfAdoptionMember_E62DBBAB877276B92642A70C4603A430" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_AccountingStandardsUpdateASU201616Member" xlink:label="loc_otex_AccountingStandardsUpdateASU201616Member_70102F603350B2CF9FCEA710EDBF9855" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_E62DBBAB877276B92642A70C4603A430" xlink:to="loc_otex_AccountingStandardsUpdateASU201616Member_70102F603350B2CF9FCEA710EDBF9855" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountingStandardsUpdate201409Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201409Member_4D6EF436C2FFDE47E8BDA70C46739CBE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_E62DBBAB877276B92642A70C4603A430" xlink:to="loc_us-gaap_AccountingStandardsUpdate201409Member_4D6EF436C2FFDE47E8BDA70C46739CBE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_519E84CAEADF2EBCAD3EA70C4673917C" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaap_SharesIssued_B48C1FC9EFA06DA242D1A70C4674E370" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_SharesIssued_B48C1FC9EFA06DA242D1A70C4674E370" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7A825D034E75563A4784A70C4674D0F3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7A825D034E75563A4784A70C4674D0F3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharebasedCompensationAbstract" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharebasedCompensationAbstract_EC65CDF3D6F1E7B8E872A70C46756C06" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharebasedCompensationAbstract_EC65CDF3D6F1E7B8E872A70C46756C06" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_EA4781198CA9D1A7C942A70C4675C311" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharebasedCompensationAbstract_EC65CDF3D6F1E7B8E872A70C46756C06" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_EA4781198CA9D1A7C942A70C4675C311" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_1AF9041D03FA4DA44ADFA70C4675494E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharebasedCompensationAbstract_EC65CDF3D6F1E7B8E872A70C46756C06" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_1AF9041D03FA4DA44ADFA70C4675494E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_3C8EA3B7C439DD537E64A70C4675B859" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharebasedCompensationAbstract_EC65CDF3D6F1E7B8E872A70C46756C06" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_3C8EA3B7C439DD537E64A70C4675B859" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_AC8460A2B9EE8E278ABCA70C4676A9D2" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharebasedCompensationAbstract_EC65CDF3D6F1E7B8E872A70C46756C06" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_AC8460A2B9EE8E278ABCA70C4676A9D2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_5269A480A27EF720868BA70C46760934" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_5269A480A27EF720868BA70C46760934" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_8CE984C6D0F1BF5ADDB7A70C467657A9" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_8CE984C6D0F1BF5ADDB7A70C467657A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_5C0DE521E6FFC15F35BAA70C467722A8" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_5C0DE521E6FFC15F35BAA70C467722A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueTreasuryStockReissued" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueTreasuryStockReissued_BEBBE7C8BEAE05E36655A70C46778D5A" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueTreasuryStockReissued_BEBBE7C8BEAE05E36655A70C46778D5A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued_83770122CBB86C451594A70C4677373E" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued_83770122CBB86C451594A70C4677373E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Dividends" xlink:label="loc_us-gaap_Dividends_D296DA38E1395263B3DCA70C46774719" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_Dividends_D296DA38E1395263B3DCA70C46774719" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_7CDD625260D5B90D2A0AA70C4677A15B" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_7CDD625260D5B90D2A0AA70C4677A15B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MinorityInterestDecreaseFromRedemptions" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_BEF74B9725CD0B7EB61EA70C4677F408" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_BEF74B9725CD0B7EB61EA70C4677F408" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_6795E096CDD7E67615F5A70C4678476B" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_E66632B98666D3A50045A70C46738300" xlink:to="loc_us-gaap_ProfitLoss_6795E096CDD7E67615F5A70C4678476B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ConsolidatedStatementsOfShareholdersEquityParenthetical" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/CoverPage" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/DerivativeInstrumentsAndHedgingActivities" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/DerivativeInstrumentsAndHedgingActivitiesEffectsOnIncomeAndOtherComprehensiveIncomeOciDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativesFairValueLineItems" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_CCB2D336428CA54DE7C75F1CF13BDCF4" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_FE1177A1C4FC682DB9205F1CF1385B83" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_CCB2D336428CA54DE7C75F1CF13BDCF4" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_FE1177A1C4FC682DB9205F1CF1385B83" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_813F5960C0E46E374DCA5F1CF1399FD7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_FE1177A1C4FC682DB9205F1CF1385B83" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_813F5960C0E46E374DCA5F1CF1399FD7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_5E7D386ADB764EA8D8F05F1CF1396FD8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_813F5960C0E46E374DCA5F1CF1399FD7" xlink:to="loc_us-gaap_HedgingRelationshipDomain_5E7D386ADB764EA8D8F05F1CF1396FD8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_5E7D386ADB764EA8D8F05F1CF1396FD8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_813F5960C0E46E374DCA5F1CF1399FD7" xlink:to="loc_us-gaap_HedgingRelationshipDomain_5E7D386ADB764EA8D8F05F1CF1396FD8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashFlowHedgingMember" xlink:label="loc_us-gaap_CashFlowHedgingMember_C178651CB0F0009A8AC45F1CF1398C67" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_5E7D386ADB764EA8D8F05F1CF1396FD8" xlink:to="loc_us-gaap_CashFlowHedgingMember_C178651CB0F0009A8AC45F1CF1398C67" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_308076F0289DD4EC2AB95F1CF1391FE5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_FE1177A1C4FC682DB9205F1CF1385B83" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_308076F0289DD4EC2AB95F1CF1391FE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_0365F85988229475F5515F1CF13A96B5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_308076F0289DD4EC2AB95F1CF1391FE5" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_0365F85988229475F5515F1CF13A96B5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_0365F85988229475F5515F1CF13A96B5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_308076F0289DD4EC2AB95F1CF1391FE5" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_0365F85988229475F5515F1CF13A96B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeForwardMember" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_1CABCDAC1FF25075406A5F1CF13AF191" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_0365F85988229475F5515F1CF13A96B5" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_1CABCDAC1FF25075406A5F1CF13AF191" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_72B51820A9D052BD8E645F1CF13A1CC1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_FE1177A1C4FC682DB9205F1CF1385B83" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_72B51820A9D052BD8E645F1CF13A1CC1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_788826EDD5A1DC7E05C95F1CF13BBE65_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_72B51820A9D052BD8E645F1CF13A1CC1" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_788826EDD5A1DC7E05C95F1CF13BBE65_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_788826EDD5A1DC7E05C95F1CF13BBE65" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_72B51820A9D052BD8E645F1CF13A1CC1" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_788826EDD5A1DC7E05C95F1CF13BBE65" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingExpenseMember" xlink:label="loc_us-gaap_OperatingExpenseMember_7C33FF04F8263B8335395F1CF13B8228" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_788826EDD5A1DC7E05C95F1CF13BBE65" xlink:to="loc_us-gaap_OperatingExpenseMember_7C33FF04F8263B8335395F1CF13B8228" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_0A72979C6684EA8E6D2B5F1CF13CA843" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_CCB2D336428CA54DE7C75F1CF13BDCF4" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_0A72979C6684EA8E6D2B5F1CF13CA843" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_943A985314DF96CD75DF5F1CF13CF146" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_CCB2D336428CA54DE7C75F1CF13BDCF4" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_943A985314DF96CD75DF5F1CF13CF146" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_479E855C2D18421AAA4C5F1CF13CC328" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_CCB2D336428CA54DE7C75F1CF13BDCF4" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_479E855C2D18421AAA4C5F1CF13CC328" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_3481B38D1A0D050C232F5F1CF13C862C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_CCB2D336428CA54DE7C75F1CF13BDCF4" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_3481B38D1A0D050C232F5F1CF13C862C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/DerivativeInstrumentsAndHedgingActivitiesFairValueInCondensedConsolidatedBalanceSheetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativesFairValueLineItems" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_785345C5FE852BE3FA535F1CEE7F1E78" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_F34E2B96323F1EA481A25F1CEE7AA6A6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_785345C5FE852BE3FA535F1CEE7F1E78" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_F34E2B96323F1EA481A25F1CEE7AA6A6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_59060E88F3415E139B885F1CEE7AD261" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_F34E2B96323F1EA481A25F1CEE7AA6A6" xlink:to="loc_srt_RangeAxis_59060E88F3415E139B885F1CEE7AD261" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_7B5579AE331A1A3AD4075F1CEE7A87C5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_59060E88F3415E139B885F1CEE7AD261" xlink:to="loc_srt_RangeMember_7B5579AE331A1A3AD4075F1CEE7A87C5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_7B5579AE331A1A3AD4075F1CEE7A87C5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_59060E88F3415E139B885F1CEE7AD261" xlink:to="loc_srt_RangeMember_7B5579AE331A1A3AD4075F1CEE7A87C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_792D2E01B9F9D2532EEC5F1CEE7B61EA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7B5579AE331A1A3AD4075F1CEE7A87C5" xlink:to="loc_srt_MinimumMember_792D2E01B9F9D2532EEC5F1CEE7B61EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_B6C97D4FA2F88EA955065F1CEE7BFA29" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7B5579AE331A1A3AD4075F1CEE7A87C5" xlink:to="loc_srt_MaximumMember_B6C97D4FA2F88EA955065F1CEE7BFA29" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_EE445473FB0BDBF644675F1CEE7BBBEF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_F34E2B96323F1EA481A25F1CEE7AA6A6" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_EE445473FB0BDBF644675F1CEE7BBBEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_4943EE3486F1C2D046855F1CEE7B9132_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_EE445473FB0BDBF644675F1CEE7BBBEF" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_4943EE3486F1C2D046855F1CEE7B9132_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_4943EE3486F1C2D046855F1CEE7B9132" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_EE445473FB0BDBF644675F1CEE7BBBEF" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_4943EE3486F1C2D046855F1CEE7B9132" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesMember" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_A5D6C2D3A8503A3952CC5F1CEE7C6B91" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_4943EE3486F1C2D046855F1CEE7B9132" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_A5D6C2D3A8503A3952CC5F1CEE7C6B91" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember" xlink:label="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_FF6C7568596B43C1FA955F1CEE7C316D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_4943EE3486F1C2D046855F1CEE7B9132" xlink:to="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_FF6C7568596B43C1FA955F1CEE7C316D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_21AB01316A4FB32EEBA95F1CEE7C0F70" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_F34E2B96323F1EA481A25F1CEE7AA6A6" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_21AB01316A4FB32EEBA95F1CEE7C0F70" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_8B1ACBF04A6428CE32DC5F1CEE7DBF65_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_21AB01316A4FB32EEBA95F1CEE7C0F70" xlink:to="loc_us-gaap_HedgingRelationshipDomain_8B1ACBF04A6428CE32DC5F1CEE7DBF65_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_8B1ACBF04A6428CE32DC5F1CEE7DBF65" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_21AB01316A4FB32EEBA95F1CEE7C0F70" xlink:to="loc_us-gaap_HedgingRelationshipDomain_8B1ACBF04A6428CE32DC5F1CEE7DBF65" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashFlowHedgingMember" xlink:label="loc_us-gaap_CashFlowHedgingMember_26D2D6BE539BF5B9E3E85F1CEE7D047E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_8B1ACBF04A6428CE32DC5F1CEE7DBF65" xlink:to="loc_us-gaap_CashFlowHedgingMember_26D2D6BE539BF5B9E3E85F1CEE7D047E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_4EB29678AB450FC0A0275F1CEE7D4CCA" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_F34E2B96323F1EA481A25F1CEE7AA6A6" xlink:to="loc_us-gaap_HedgingDesignationAxis_4EB29678AB450FC0A0275F1CEE7D4CCA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_B12E1041CC6F9D5054385F1CEE7DBFD8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_4EB29678AB450FC0A0275F1CEE7D4CCA" xlink:to="loc_us-gaap_HedgingDesignationDomain_B12E1041CC6F9D5054385F1CEE7DBFD8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_B12E1041CC6F9D5054385F1CEE7DBFD8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_4EB29678AB450FC0A0275F1CEE7D4CCA" xlink:to="loc_us-gaap_HedgingDesignationDomain_B12E1041CC6F9D5054385F1CEE7DBFD8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2EA0EAC9E35EADB94F445F1CEE7EBA41" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_B12E1041CC6F9D5054385F1CEE7DBFD8" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2EA0EAC9E35EADB94F445F1CEE7EBA41" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_4C5EBBB1CD0C18DA2A9D5F1CEE7EFEAA" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_F34E2B96323F1EA481A25F1CEE7AA6A6" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_4C5EBBB1CD0C18DA2A9D5F1CEE7EFEAA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_6385CB070339CBE388C95F1CEE7E7BC4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_4C5EBBB1CD0C18DA2A9D5F1CEE7EFEAA" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_6385CB070339CBE388C95F1CEE7E7BC4_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_6385CB070339CBE388C95F1CEE7E7BC4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_4C5EBBB1CD0C18DA2A9D5F1CEE7EFEAA" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_6385CB070339CBE388C95F1CEE7E7BC4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeForwardMember" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_1582D30A11460342C08B5F1CEE7F13D2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_6385CB070339CBE388C95F1CEE7E7BC4" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_1582D30A11460342C08B5F1CEE7F13D2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeTermOfContract" xlink:label="loc_us-gaap_DerivativeTermOfContract_DB902BA218BE308EED6B5F1CEE7FEF3E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_785345C5FE852BE3FA535F1CEE7F1E78" xlink:to="loc_us-gaap_DerivativeTermOfContract_DB902BA218BE308EED6B5F1CEE7FEF3E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeNotionalAmount" xlink:label="loc_us-gaap_DerivativeNotionalAmount_26CC3AD778244BB081E25F1CEE7FDE6A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_785345C5FE852BE3FA535F1CEE7F1E78" xlink:to="loc_us-gaap_DerivativeNotionalAmount_26CC3AD778244BB081E25F1CEE7FDE6A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_95AB0B700772FC2C19035F1CEE7F0A2F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_785345C5FE852BE3FA535F1CEE7F1E78" xlink:to="loc_us-gaap_DerivativeLiabilities_95AB0B700772FC2C19035F1CEE7F0A2F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_7FDBD9FA21B6F581EB825F1CEE80E751" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_785345C5FE852BE3FA535F1CEE7F1E78" xlink:to="loc_us-gaap_DerivativeAssets_7FDBD9FA21B6F581EB825F1CEE80E751" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/DerivativeInstrumentsAndHedgingActivitiesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/EarningsPerShare" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/EarningsPerShareDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/EarningsPerShareTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/FairValueMeasurement" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/FairValueMeasurementDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_70B6D12CDA6F3A6972F25F1CEB44738A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_D1CB61703E0BB0B0CF075F1CEB3DE3DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_70B6D12CDA6F3A6972F25F1CEB44738A" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_D1CB61703E0BB0B0CF075F1CEB3DE3DE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_72BCB3758DD660E6C5D65F1CEB3D3D62" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_D1CB61703E0BB0B0CF075F1CEB3DE3DE" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_72BCB3758DD660E6C5D65F1CEB3D3D62" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_CD8237772546C3C06F965F1CEB424AE3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_72BCB3758DD660E6C5D65F1CEB3D3D62" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_CD8237772546C3C06F965F1CEB424AE3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_CD8237772546C3C06F965F1CEB424AE3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_72BCB3758DD660E6C5D65F1CEB3D3D62" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_CD8237772546C3C06F965F1CEB424AE3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_CE50FD5B6FC67224B98D5F1CEB4366B2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_CD8237772546C3C06F965F1CEB424AE3" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_CE50FD5B6FC67224B98D5F1CEB4366B2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_46E424696C7E9506D84F5F1CEB437BBC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_D1CB61703E0BB0B0CF075F1CEB3DE3DE" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_46E424696C7E9506D84F5F1CEB437BBC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_228538661BF0BCFB81C25F1CEB43BFAD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_46E424696C7E9506D84F5F1CEB437BBC" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_228538661BF0BCFB81C25F1CEB43BFAD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_228538661BF0BCFB81C25F1CEB43BFAD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_46E424696C7E9506D84F5F1CEB437BBC" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_228538661BF0BCFB81C25F1CEB43BFAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_CD62E575574F34E725745F1CEB441CAD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_228538661BF0BCFB81C25F1CEB43BFAD" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_CD62E575574F34E725745F1CEB441CAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_4FA00BB438A005755F175F1CEB4459D3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_70B6D12CDA6F3A6972F25F1CEB44738A" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_4FA00BB438A005755F175F1CEB4459D3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_D1AF3857E82DFDD8EBCE5F1CEB459EDF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_4FA00BB438A005755F175F1CEB4459D3" xlink:to="loc_us-gaap_DerivativeAssets_D1AF3857E82DFDD8EBCE5F1CEB459EDF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_4A13E99B46E274262B045F1CEB455D2E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_4FA00BB438A005755F175F1CEB4459D3" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_4A13E99B46E274262B045F1CEB455D2E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_F8B3D5D27B96D8D74B185F1CEB456DF0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_70B6D12CDA6F3A6972F25F1CEB44738A" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_F8B3D5D27B96D8D74B185F1CEB456DF0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_2BBB891D0277381A110E5F1CEB468309" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_F8B3D5D27B96D8D74B185F1CEB456DF0" xlink:to="loc_us-gaap_DerivativeLiabilities_2BBB891D0277381A110E5F1CEB468309" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancialLiabilitiesFairValueDisclosure" xlink:label="loc_us-gaap_FinancialLiabilitiesFairValueDisclosure_507055B2BCC29DB707285F1CEB464D2A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_F8B3D5D27B96D8D74B185F1CEB456DF0" xlink:to="loc_us-gaap_FinancialLiabilitiesFairValueDisclosure_507055B2BCC29DB707285F1CEB464D2A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/FairValueMeasurementTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/Goodwill" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/GoodwillDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillLineItems" xlink:label="loc_us-gaap_GoodwillLineItems_D5246CE1E15ACA4EEA145F1CF262516A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_4543290BF50CE19D3B875F1CF2609187" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_D5246CE1E15ACA4EEA145F1CF262516A" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_4543290BF50CE19D3B875F1CF2609187" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_929AA81FF6D9FCCF92715F1CF260EDFE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_4543290BF50CE19D3B875F1CF2609187" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_929AA81FF6D9FCCF92715F1CF260EDFE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01E97366EC781128152C5F1CF2615C63_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_929AA81FF6D9FCCF92715F1CF260EDFE" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01E97366EC781128152C5F1CF2615C63_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01E97366EC781128152C5F1CF2615C63" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_929AA81FF6D9FCCF92715F1CF260EDFE" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01E97366EC781128152C5F1CF2615C63" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CatalystRepositorySystemsIncMember" xlink:label="loc_otex_CatalystRepositorySystemsIncMember_29F032E22EC521007A405F1CF261F7EF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01E97366EC781128152C5F1CF2615C63" xlink:to="loc_otex_CatalystRepositorySystemsIncMember_29F032E22EC521007A405F1CF261F7EF" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_LiaisonTechnologiesInc.Member" xlink:label="loc_otex_LiaisonTechnologiesInc.Member_60998D7191EAB88F51D05F1CF261969F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01E97366EC781128152C5F1CF2615C63" xlink:to="loc_otex_LiaisonTechnologiesInc.Member_60998D7191EAB88F51D05F1CF261969F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_XMediusMember" xlink:label="loc_otex_XMediusMember_90C25FAB59694286B6095F1CF26133D2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01E97366EC781128152C5F1CF2615C63" xlink:to="loc_otex_XMediusMember_90C25FAB59694286B6095F1CF26133D2" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CarboniteInc.Member" xlink:label="loc_otex_CarboniteInc.Member_902E4F66E5BECD94E6765F1CF2625FAB" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01E97366EC781128152C5F1CF2615C63" xlink:to="loc_otex_CarboniteInc.Member_902E4F66E5BECD94E6765F1CF2625FAB" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DynamicSolutionsGroupIncMember" xlink:label="loc_otex_DynamicSolutionsGroupIncMember_A408C44086352254C2485F1CF2623906" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01E97366EC781128152C5F1CF2615C63" xlink:to="loc_otex_DynamicSolutionsGroupIncMember_A408C44086352254C2485F1CF2623906" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillRollForward" xlink:label="loc_us-gaap_GoodwillRollForward_4AF7DA916AE2549CB7105F1CF262F8D7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_D5246CE1E15ACA4EEA145F1CF262516A" xlink:to="loc_us-gaap_GoodwillRollForward_4AF7DA916AE2549CB7105F1CF262F8D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_727E216D29AF9784B1105F1CF262D086" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_4AF7DA916AE2549CB7105F1CF262F8D7" xlink:to="loc_us-gaap_Goodwill_727E216D29AF9784B1105F1CF262D086" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_52528884371B3FAAB4535F1CF2636501" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_4AF7DA916AE2549CB7105F1CF262F8D7" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_52528884371B3FAAB4535F1CF2636501" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_EA7627BD5EE4B6D4EB205F1CF2633FE8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_4AF7DA916AE2549CB7105F1CF262F8D7" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_EA7627BD5EE4B6D4EB205F1CF2633FE8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_581E53B37AD4843A9DB75F1CF263AEA2" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_4AF7DA916AE2549CB7105F1CF262F8D7" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_581E53B37AD4843A9DB75F1CF263AEA2" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/GoodwillTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/GuaranteesAndContingencies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/GuaranteesAndContingenciesAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_87BB251E657CAAEF26D9974620A80061" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:to="loc_us-gaap_LossContingenciesTable_87BB251E657CAAEF26D9974620A80061" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_C79EBF2CC19D595F6B55974620A83701" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_87BB251E657CAAEF26D9974620A80061" xlink:to="loc_srt_RangeAxis_C79EBF2CC19D595F6B55974620A83701" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_27287132A34D765DD446974620A98AA5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_C79EBF2CC19D595F6B55974620A83701" xlink:to="loc_srt_RangeMember_27287132A34D765DD446974620A98AA5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_27287132A34D765DD446974620A98AA5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_C79EBF2CC19D595F6B55974620A83701" xlink:to="loc_srt_RangeMember_27287132A34D765DD446974620A98AA5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_4B5A63F32E8F32C6182F974620A94C28" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_27287132A34D765DD446974620A98AA5" xlink:to="loc_srt_MinimumMember_4B5A63F32E8F32C6182F974620A94C28" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_0201DD9869E9900BDD06974620A9E316" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_27287132A34D765DD446974620A98AA5" xlink:to="loc_srt_MaximumMember_0201DD9869E9900BDD06974620A9E316" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityNameAxis" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameAxis_D261E13180D4C4AF5B36974620A9EDC4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_87BB251E657CAAEF26D9974620A80061" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameAxis_D261E13180D4C4AF5B36974620A9EDC4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityNameDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_04B299F38EE1F5092E4A974620AAC858_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_D261E13180D4C4AF5B36974620A9EDC4" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_04B299F38EE1F5092E4A974620AAC858_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityNameDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_04B299F38EE1F5092E4A974620AAC858" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_D261E13180D4C4AF5B36974620A9EDC4" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_04B299F38EE1F5092E4A974620AAC858" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InternalRevenueServiceIRSMember" xlink:label="loc_us-gaap_InternalRevenueServiceIRSMember_F92B5D4ECBDDE013D344974620AA0EF0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameDomain_04B299F38EE1F5092E4A974620AAC858" xlink:to="loc_us-gaap_InternalRevenueServiceIRSMember_F92B5D4ECBDDE013D344974620AA0EF0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CanadaRevenueAgencyMember" xlink:label="loc_us-gaap_CanadaRevenueAgencyMember_48D02C7773A4B1FCFC4A974620AA9319" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameDomain_04B299F38EE1F5092E4A974620AAC858" xlink:to="loc_us-gaap_CanadaRevenueAgencyMember_48D02C7773A4B1FCFC4A974620AA9319" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxPeriodAxis" xlink:label="loc_us-gaap_TaxPeriodAxis_A414A2E25F0B09084CAF974620ABD6E1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_87BB251E657CAAEF26D9974620A80061" xlink:to="loc_us-gaap_TaxPeriodAxis_A414A2E25F0B09084CAF974620ABD6E1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxPeriodDomain" xlink:label="loc_us-gaap_TaxPeriodDomain_F2ACF9001D13C5947843974620AB0301_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TaxPeriodAxis_A414A2E25F0B09084CAF974620ABD6E1" xlink:to="loc_us-gaap_TaxPeriodDomain_F2ACF9001D13C5947843974620AB0301_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxPeriodDomain" xlink:label="loc_us-gaap_TaxPeriodDomain_F2ACF9001D13C5947843974620AB0301" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TaxPeriodAxis_A414A2E25F0B09084CAF974620ABD6E1" xlink:to="loc_us-gaap_TaxPeriodDomain_F2ACF9001D13C5947843974620AB0301" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxYear2010Member" xlink:label="loc_us-gaap_TaxYear2010Member_42280EDF8174201E39D0974620AB0067" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_F2ACF9001D13C5947843974620AB0301" xlink:to="loc_us-gaap_TaxYear2010Member_42280EDF8174201E39D0974620AB0067" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxYear2012Member" xlink:label="loc_us-gaap_TaxYear2012Member_A53EE89F4D31CA7DA01D974620ABC83A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_F2ACF9001D13C5947843974620AB0301" xlink:to="loc_us-gaap_TaxYear2012Member_A53EE89F4D31CA7DA01D974620ABC83A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxYear2013Member" xlink:label="loc_us-gaap_TaxYear2013Member_66C0E04661A8B747D012974620AC0DDF" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_F2ACF9001D13C5947843974620AB0301" xlink:to="loc_us-gaap_TaxYear2013Member_66C0E04661A8B747D012974620AC0DDF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxYear2014Member" xlink:label="loc_us-gaap_TaxYear2014Member_0368A97CCF3C3C5B9836974620ACA747" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_F2ACF9001D13C5947843974620AB0301" xlink:to="loc_us-gaap_TaxYear2014Member_0368A97CCF3C3C5B9836974620ACA747" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxYear2015Member" xlink:label="loc_us-gaap_TaxYear2015Member_75456BB363E7EE473DAD974AFD776584" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_F2ACF9001D13C5947843974620AB0301" xlink:to="loc_us-gaap_TaxYear2015Member_75456BB363E7EE473DAD974AFD776584" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_725284DD1CCB24CEF495974620ACD0DC" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_87BB251E657CAAEF26D9974620A80061" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_725284DD1CCB24CEF495974620ACD0DC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_AA8BA1C890CBE0BE8D95974620AC281D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_725284DD1CCB24CEF495974620ACD0DC" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_AA8BA1C890CBE0BE8D95974620AC281D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_AA8BA1C890CBE0BE8D95974620AC281D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_725284DD1CCB24CEF495974620ACD0DC" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_AA8BA1C890CBE0BE8D95974620AC281D" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSIndiaMember" xlink:label="loc_otex_GXSIndiaMember_710159425F97C91FA8EA974620AD716C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_AA8BA1C890CBE0BE8D95974620AC281D" xlink:to="loc_otex_GXSIndiaMember_710159425F97C91FA8EA974620AD716C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss" xlink:label="loc_us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss_C37A7EBB7E5D4C3C89E1974620AD7E40" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:to="loc_us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss_C37A7EBB7E5D4C3C89E1974620AD7E40" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_IncomeTaxPenaltyRate" xlink:label="loc_otex_IncomeTaxPenaltyRate_6F65BBB2F5473B851AE1974620ADE67B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:to="loc_otex_IncomeTaxPenaltyRate_6F65BBB2F5473B851AE1974620ADE67B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExaminationIncreaseDecreaseInLiabilityFromPriorYear" xlink:label="loc_us-gaap_IncomeTaxExaminationIncreaseDecreaseInLiabilityFromPriorYear_E11AFA96E2CA6BD71FCA974620AD3886" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:to="loc_us-gaap_IncomeTaxExaminationIncreaseDecreaseInLiabilityFromPriorYear_E11AFA96E2CA6BD71FCA974620AD3886" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_IncomeTaxExaminationEstimateOfPossibleLossTax" xlink:label="loc_otex_IncomeTaxExaminationEstimateOfPossibleLossTax_68F001B97ADDD6A52B1A974620AE9A88" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:to="loc_otex_IncomeTaxExaminationEstimateOfPossibleLossTax_68F001B97ADDD6A52B1A974620AE9A88" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_IncomeTaxExaminationEstimateOfPossibleLossPenalties" xlink:label="loc_otex_IncomeTaxExaminationEstimateOfPossibleLossPenalties_C8A2F069BC18B25D9F8D974620AE0109" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:to="loc_otex_IncomeTaxExaminationEstimateOfPossibleLossPenalties_C8A2F069BC18B25D9F8D974620AE0109" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_IncomeTaxExaminationEstimateOfPossibleLossInterest" xlink:label="loc_otex_IncomeTaxExaminationEstimateOfPossibleLossInterest_D5EA1E0B6048709407F6974620AE38B1" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:to="loc_otex_IncomeTaxExaminationEstimateOfPossibleLossInterest_D5EA1E0B6048709407F6974620AE38B1" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_IncomeTaxExaminationEstimateofIncreasetoTaxableIncome" xlink:label="loc_otex_IncomeTaxExaminationEstimateofIncreasetoTaxableIncome_7CCDBC96941F730DD4A3974620AEFC2C" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:to="loc_otex_IncomeTaxExaminationEstimateofIncreasetoTaxableIncome_7CCDBC96941F730DD4A3974620AEFC2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyAccrualAtCarryingValue" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_5632F3714DAEC59BD949974620AEBF81" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_9F29167FCE1971008D2B974620ADBB73" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_5632F3714DAEC59BD949974620AEBF81" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/GuaranteesAndContingenciesScheduleOfContractualObligationsWithMinimumPaymentsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_76EE48BA553E92B6C4EC5F1CF3479C62" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_9719EB195731D20587E85F1CF345D13D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_76EE48BA553E92B6C4EC5F1CF3479C62" xlink:to="loc_us-gaap_DebtInstrumentTable_9719EB195731D20587E85F1CF345D13D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_4414ECDC9DD43A1CDACE5F1CF34592B3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9719EB195731D20587E85F1CF345D13D" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_4414ECDC9DD43A1CDACE5F1CF34592B3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_5EAC9037BA2472D6EDC55F1CF3453102_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_4414ECDC9DD43A1CDACE5F1CF34592B3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_5EAC9037BA2472D6EDC55F1CF3453102_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_5EAC9037BA2472D6EDC55F1CF3453102" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_4414ECDC9DD43A1CDACE5F1CF34592B3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_5EAC9037BA2472D6EDC55F1CF3453102" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember" xlink:label="loc_us-gaap_LineOfCreditMember_090B596077882B493D2F5F1CF34678BC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_5EAC9037BA2472D6EDC55F1CF3453102" xlink:to="loc_us-gaap_LineOfCreditMember_090B596077882B493D2F5F1CF34678BC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_C95B45E13C05618539845F1CF346830C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9719EB195731D20587E85F1CF345D13D" xlink:to="loc_us-gaap_CreditFacilityAxis_C95B45E13C05618539845F1CF346830C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_76E84358FE342CEEF13B5F1CF3469EE5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_C95B45E13C05618539845F1CF346830C" xlink:to="loc_us-gaap_CreditFacilityDomain_76E84358FE342CEEF13B5F1CF3469EE5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_76E84358FE342CEEF13B5F1CF3469EE5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_C95B45E13C05618539845F1CF346830C" xlink:to="loc_us-gaap_CreditFacilityDomain_76E84358FE342CEEF13B5F1CF3469EE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_4C1F5E26AF88C5154D4B5F1CF347D3A7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_76E84358FE342CEEF13B5F1CF3469EE5" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_4C1F5E26AF88C5154D4B5F1CF347D3A7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_B444923AF43121D665985F1CF347F007" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_76EE48BA553E92B6C4EC5F1CF3479C62" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_B444923AF43121D665985F1CF347F007" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/GuaranteesAndContingenciesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxes" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxesAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLossCarryforwardsLineItems" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLossCarryforwardsTable" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable_5FAA1BAE198C9E4DE6B6A0D795FE8000" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable_5FAA1BAE198C9E4DE6B6A0D795FE8000" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_302C1A6CB9D6A6D1BC42A0D795FE3ECD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_5FAA1BAE198C9E4DE6B6A0D795FE8000" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_302C1A6CB9D6A6D1BC42A0D795FE3ECD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_AB4C029454310D8C0F65A0D795FF10A5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_302C1A6CB9D6A6D1BC42A0D795FE3ECD" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_AB4C029454310D8C0F65A0D795FF10A5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_AB4C029454310D8C0F65A0D795FF10A5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_302C1A6CB9D6A6D1BC42A0D795FE3ECD" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_AB4C029454310D8C0F65A0D795FF10A5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticCountryMember" xlink:label="loc_us-gaap_DomesticCountryMember_A9D447B7511E99934642A0D795FFE8C7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_AB4C029454310D8C0F65A0D795FF10A5" xlink:to="loc_us-gaap_DomesticCountryMember_A9D447B7511E99934642A0D795FFE8C7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCountryMember" xlink:label="loc_us-gaap_ForeignCountryMember_4120358FE82AB65C7F2FA0D795FFCB59" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_AB4C029454310D8C0F65A0D795FF10A5" xlink:to="loc_us-gaap_ForeignCountryMember_4120358FE82AB65C7F2FA0D795FFCB59" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_F8D4EE6319E549ADDFE4A0D79600620A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_F8D4EE6319E549ADDFE4A0D79600620A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_IncreaseDecreaseinIncomeTaxExpenseBenefit" xlink:label="loc_otex_IncreaseDecreaseinIncomeTaxExpenseBenefit_B989BA1FF8B1F9816CACA0D7960065B5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_IncreaseDecreaseinIncomeTaxExpenseBenefit_B989BA1FF8B1F9816CACA0D7960065B5" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EffectiveIncomeTaxRateReconciliationatFederalStatutoryIncomeTaxRateIncreaseDecreaseAmount" xlink:label="loc_otex_EffectiveIncomeTaxRateReconciliationatFederalStatutoryIncomeTaxRateIncreaseDecreaseAmount_BBBAAEB6DE5B34C12F4DA0D7960040B3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_EffectiveIncomeTaxRateReconciliationatFederalStatutoryIncomeTaxRateIncreaseDecreaseAmount_BBBAAEB6DE5B34C12F4DA0D7960040B3" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EffectiveIncomeTaxRateReconciliationEffectofChangesinUnrecognizedTaxBenefitsIncreaseDecreaseAmount" xlink:label="loc_otex_EffectiveIncomeTaxRateReconciliationEffectofChangesinUnrecognizedTaxBenefitsIncreaseDecreaseAmount_CB1B37A96A103903A94AA0D796001BC8" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_EffectiveIncomeTaxRateReconciliationEffectofChangesinUnrecognizedTaxBenefitsIncreaseDecreaseAmount_CB1B37A96A103903A94AA0D796001BC8" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EffectiveIncomeTaxRateReconciliationImpactoftheCARESActAmount" xlink:label="loc_otex_EffectiveIncomeTaxRateReconciliationImpactoftheCARESActAmount_8410A958AB465F3F9E44A0D796011D2C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_EffectiveIncomeTaxRateReconciliationImpactoftheCARESActAmount_8410A958AB465F3F9E44A0D796011D2C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EffectiveIncomeTaxRateReconciliationInternalReorganizationIncreaseDecreaseAmount" xlink:label="loc_otex_EffectiveIncomeTaxRateReconciliationInternalReorganizationIncreaseDecreaseAmount_C44F369C86AE7CA451A3A0D79601E428" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_EffectiveIncomeTaxRateReconciliationInternalReorganizationIncreaseDecreaseAmount_C44F369C86AE7CA451A3A0D79601E428" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EffectiveIncomeTaxRateReconciliationImpactOfTaxCutsAndJobsActBaseErosionAvoidanceTaxIncreaseDecreaseAmount" xlink:label="loc_otex_EffectiveIncomeTaxRateReconciliationImpactOfTaxCutsAndJobsActBaseErosionAvoidanceTaxIncreaseDecreaseAmount_BCB4BDBD13C6D242D2C0A0D79601E243" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_EffectiveIncomeTaxRateReconciliationImpactOfTaxCutsAndJobsActBaseErosionAvoidanceTaxIncreaseDecreaseAmount_BCB4BDBD13C6D242D2C0A0D79601E243" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReconciliationRepatriationOfForeignEarnings" xlink:label="loc_us-gaap_IncomeTaxReconciliationRepatriationOfForeignEarnings_F9A87EB071448F273321A0D79601B311" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_us-gaap_IncomeTaxReconciliationRepatriationOfForeignEarnings_F9A87EB071448F273321A0D79601B311" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EffectiveIncomeTaxRateReconciliationWithholdingTaxesIncreaseDecreaseAmount" xlink:label="loc_otex_EffectiveIncomeTaxRateReconciliationWithholdingTaxesIncreaseDecreaseAmount_B9AF48E29858174E339DA0D796014F0E" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_EffectiveIncomeTaxRateReconciliationWithholdingTaxesIncreaseDecreaseAmount_B9AF48E29858174E339DA0D796014F0E" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsValuationAllowanceIncreaseDecreaseAmount" xlink:label="loc_otex_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsValuationAllowanceIncreaseDecreaseAmount_45919250AA249C2C85ACA0D7960262D4" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsValuationAllowanceIncreaseDecreaseAmount_45919250AA249C2C85ACA0D7960262D4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="loc_us-gaap_OperatingLossCarryforwards_A827C4ADD3608038613CA0D79602DBEC" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_us-gaap_OperatingLossCarryforwards_A827C4ADD3608038613CA0D79602DBEC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration_EDE65F6500028E8E3993A0D79602D93A" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration_EDE65F6500028E8E3993A0D79602D93A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InvestmentTaxCredit" xlink:label="loc_us-gaap_InvestmentTaxCredit_1F46E8959C0DD414A184A0D796022960" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_us-gaap_InvestmentTaxCredit_1F46E8959C0DD414A184A0D796022960" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_UnrecognizedTaxBenefitsOfDeferredTaxAssetsOffsetbyValuationAllowance" xlink:label="loc_otex_UnrecognizedTaxBenefitsOfDeferredTaxAssetsOffsetbyValuationAllowance_504DB7994E30FE7403AEA0D79602F4DC" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_UnrecognizedTaxBenefitsOfDeferredTaxAssetsOffsetbyValuationAllowance_504DB7994E30FE7403AEA0D79602F4DC" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_UnrecognizedTaxBenefitsthatWouldNotImpactEffectiveTaxRate" xlink:label="loc_otex_UnrecognizedTaxBenefitsthatWouldNotImpactEffectiveTaxRate_8579726840FEF754424DA1164F18E2BB" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_UnrecognizedTaxBenefitsthatWouldNotImpactEffectiveTaxRate_8579726840FEF754424DA1164F18E2BB" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_NetUnrecognizedTaxBenefitExcludingPortionOffsetbyValuationAllowance" xlink:label="loc_otex_NetUnrecognizedTaxBenefitExcludingPortionOffsetbyValuationAllowance_FDD5F38C996B1656DBBFA0D79602011F" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_otex_NetUnrecognizedTaxBenefitExcludingPortionOffsetbyValuationAllowance_FDD5F38C996B1656DBBFA0D79602011F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible" xlink:label="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_EEE3C9B3BBB05782151BA0D79603D04C" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_EEE3C9B3BBB05782151BA0D79603D04C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredTaxLiabilitiesDeferredExpenseReservesAndAccruals" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesDeferredExpenseReservesAndAccruals_9D05341E2D2AE00C3D0DA0D7960300FF" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_94531E78E01A90A3714FA0D795FF8645" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesDeferredExpenseReservesAndAccruals_9D05341E2D2AE00C3D0DA0D7960300FF" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxesChangesInBalanceOfGrossUnrecognizedTaxBenefitsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxesComponentsOfDeferredTaxAssetsAndLiabilitiesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxesComponentsOfIncomeTaxDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxesIncomeBeforeProvisionForIncomeTaxDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxesIncomeTaxReconciliationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxesInterestAccruedAndPenaltiesAccruedRelatedToIncomeTaxExpenseDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxesInterestAndPenaltiesRelatedToLiabilitiesForIncomeTaxExpenseDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/IncomeTaxesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/Leases" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/LeasesAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeLeaseDescriptionLineItems" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_D097D7B27F3DE6133E485F1CF1C2DEA5" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeLeaseDescriptionTable" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_C9EA7E7A67542D521FFC5F1CF1C0AFB2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_D097D7B27F3DE6133E485F1CF1C2DEA5" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_C9EA7E7A67542D521FFC5F1CF1C0AFB2" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_46D5FE6CFE8971CCCCA05F1CF1C088DA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_C9EA7E7A67542D521FFC5F1CF1C0AFB2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_46D5FE6CFE8971CCCCA05F1CF1C088DA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_AE75CC128A8DB13134435F1CF1C024AF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_46D5FE6CFE8971CCCCA05F1CF1C088DA" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_AE75CC128A8DB13134435F1CF1C024AF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_AE75CC128A8DB13134435F1CF1C024AF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_46D5FE6CFE8971CCCCA05F1CF1C088DA" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_AE75CC128A8DB13134435F1CF1C024AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LandMember" xlink:label="loc_us-gaap_LandMember_94FB26A5019E54EB16325F1CF1C01E22" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_AE75CC128A8DB13134435F1CF1C024AF" xlink:to="loc_us-gaap_LandMember_94FB26A5019E54EB16325F1CF1C01E22" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_144A2A4F3EB60061A3165F1CF1C146A3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_C9EA7E7A67542D521FFC5F1CF1C0AFB2" xlink:to="loc_srt_RangeAxis_144A2A4F3EB60061A3165F1CF1C146A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_7F022B79647B34E0DEE75F1CF1C14326_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_144A2A4F3EB60061A3165F1CF1C146A3" xlink:to="loc_srt_RangeMember_7F022B79647B34E0DEE75F1CF1C14326_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_7F022B79647B34E0DEE75F1CF1C14326" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_144A2A4F3EB60061A3165F1CF1C146A3" xlink:to="loc_srt_RangeMember_7F022B79647B34E0DEE75F1CF1C14326" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_4096D856396F2A7182CE5F1CF1C15AAE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7F022B79647B34E0DEE75F1CF1C14326" xlink:to="loc_srt_MinimumMember_4096D856396F2A7182CE5F1CF1C15AAE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_AE09B4110275BD02D78F5F1CF1C20386" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7F022B79647B34E0DEE75F1CF1C14326" xlink:to="loc_srt_MaximumMember_AE09B4110275BD02D78F5F1CF1C20386" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseTermOfContract" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_21349EB552079B42FA3F5F1CF1C207A2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_D097D7B27F3DE6133E485F1CF1C2DEA5" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_21349EB552079B42FA3F5F1CF1C207A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LesseeOperatingLeaseRenewalTerm" xlink:label="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_4CD5352BD22BD12852295F1CF1C2572D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_D097D7B27F3DE6133E485F1CF1C2DEA5" xlink:to="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_4CD5352BD22BD12852295F1CF1C2572D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/LeasesLeaseCostsAndOtherInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3CFABFF63B5D0FACC72481FD6736FF1A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3CFABFF63B5D0FACC72481FD6736FF1A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_E4E3CD9BDAD2801BB4F781FD67399096" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3CFABFF63B5D0FACC72481FD6736FF1A" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_E4E3CD9BDAD2801BB4F781FD67399096" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4ECBEBF7F65F922E97AE81FD67395AA6_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_E4E3CD9BDAD2801BB4F781FD67399096" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4ECBEBF7F65F922E97AE81FD67395AA6_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4ECBEBF7F65F922E97AE81FD67395AA6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_E4E3CD9BDAD2801BB4F781FD67399096" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4ECBEBF7F65F922E97AE81FD67395AA6" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CarboniteInc.Member" xlink:label="loc_otex_CarboniteInc.Member_B94DE24C1B791DD249A381FD67394C26" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4ECBEBF7F65F922E97AE81FD67395AA6" xlink:to="loc_otex_CarboniteInc.Member_B94DE24C1B791DD249A381FD67394C26" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_XMediusMember" xlink:label="loc_otex_XMediusMember_05108603998FAFE8754981FD673A40D1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4ECBEBF7F65F922E97AE81FD67395AA6" xlink:to="loc_otex_XMediusMember_05108603998FAFE8754981FD673A40D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseCost" xlink:label="loc_us-gaap_OperatingLeaseCost_D8593B9C39596AD084EF81FD673A9DBB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:to="loc_us-gaap_OperatingLeaseCost_D8593B9C39596AD084EF81FD673A9DBB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShortTermLeaseCost" xlink:label="loc_us-gaap_ShortTermLeaseCost_2EA2A4D5086F4D37AF2381FD673B5808" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:to="loc_us-gaap_ShortTermLeaseCost_2EA2A4D5086F4D37AF2381FD673B5808" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableLeaseCost" xlink:label="loc_us-gaap_VariableLeaseCost_9D74B34D946C91442B1581FD673BC555" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:to="loc_us-gaap_VariableLeaseCost_9D74B34D946C91442B1581FD673BC555" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubleaseIncome" xlink:label="loc_us-gaap_SubleaseIncome_9B49F6385ED7623C716281FD673BF8C5" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:to="loc_us-gaap_SubleaseIncome_9B49F6385ED7623C716281FD673BF8C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseCost" xlink:label="loc_us-gaap_LeaseCost_EA1AD74847058EF94C2381FD673B282E" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:to="loc_us-gaap_LeaseCost_EA1AD74847058EF94C2381FD673B282E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_B198283F29A86A593F5F81FD673C0FFC" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_B198283F29A86A593F5F81FD673C0FFC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_E5C26D8DE4040325318B81FD673C1AD7" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:to="loc_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_E5C26D8DE4040325318B81FD673C1AD7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_5355569F61A99033758E81FD673C751F" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_296152D2A97B4F7FCE7081FD673AB783" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_5355569F61A99033758E81FD673C751F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeasePayments" xlink:label="loc_us-gaap_OperatingLeasePayments_1386FCFE5C16F429378B81FD673CD969" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_5355569F61A99033758E81FD673C751F" xlink:to="loc_us-gaap_OperatingLeasePayments_1386FCFE5C16F429378B81FD673CD969" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_BA591D68C00D28C670CF81FD673D1810" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_5355569F61A99033758E81FD673C751F" xlink:to="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_BA591D68C00D28C670CF81FD673D1810" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_BusinessCombinationRecognizedIdentifiableAssetAcquiredandLiabilityAssumedOperatingLeaseRightofUseAsset" xlink:label="loc_otex_BusinessCombinationRecognizedIdentifiableAssetAcquiredandLiabilityAssumedOperatingLeaseRightofUseAsset_B1E2C45575BF9F0E43DE81FD673D8B18" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_5355569F61A99033758E81FD673C751F" xlink:to="loc_otex_BusinessCombinationRecognizedIdentifiableAssetAcquiredandLiabilityAssumedOperatingLeaseRightofUseAsset_B1E2C45575BF9F0E43DE81FD673D8B18" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/LeasesMaturityOfLeaseLiabilitiesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/LeasesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/LongTermDebt" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/LongTermDebtAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_800A309D8E1C34F1FB055F1CEC443628" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_DebtInstrumentTable_800A309D8E1C34F1FB055F1CEC443628" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_EFBCA510C08A368FC4595F1CEC456E02" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_800A309D8E1C34F1FB055F1CEC443628" xlink:to="loc_us-gaap_DebtInstrumentAxis_EFBCA510C08A368FC4595F1CEC456E02" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_CCCD196DE1C51302793F5F1CEC45ECFF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_EFBCA510C08A368FC4595F1CEC456E02" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_CCCD196DE1C51302793F5F1CEC45ECFF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_CCCD196DE1C51302793F5F1CEC45ECFF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_EFBCA510C08A368FC4595F1CEC456E02" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_CCCD196DE1C51302793F5F1CEC45ECFF" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_NotesDue2022Member" xlink:label="loc_otex_NotesDue2022Member_CEB41EDE5D7F377C75645F1CEC453D65" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_CCCD196DE1C51302793F5F1CEC45ECFF" xlink:to="loc_otex_NotesDue2022Member_CEB41EDE5D7F377C75645F1CEC453D65" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TermLoanBMember" xlink:label="loc_otex_TermLoanBMember_BE24E30C8CD973913B175F1CEC46A4F5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_CCCD196DE1C51302793F5F1CEC45ECFF" xlink:to="loc_otex_TermLoanBMember_BE24E30C8CD973913B175F1CEC46A4F5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_3738C71F59F0D24FDF1F5F1CEC468B02" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_800A309D8E1C34F1FB055F1CEC443628" xlink:to="loc_us-gaap_CreditFacilityAxis_3738C71F59F0D24FDF1F5F1CEC468B02" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_F7C4086B26596BE35A215F1CEC465DC6_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_3738C71F59F0D24FDF1F5F1CEC468B02" xlink:to="loc_us-gaap_CreditFacilityDomain_F7C4086B26596BE35A215F1CEC465DC6_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_F7C4086B26596BE35A215F1CEC465DC6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_3738C71F59F0D24FDF1F5F1CEC468B02" xlink:to="loc_us-gaap_CreditFacilityDomain_F7C4086B26596BE35A215F1CEC465DC6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_E27084A356E5EA6E7BC15F1CEC46C5DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_F7C4086B26596BE35A215F1CEC465DC6" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_E27084A356E5EA6E7BC15F1CEC46C5DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_5FDE7DB67ED8B25D06685F1CEC473629" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_800A309D8E1C34F1FB055F1CEC443628" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_5FDE7DB67ED8B25D06685F1CEC473629" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_CA42C1E08BE00106B3295F1CEC47DD09_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_5FDE7DB67ED8B25D06685F1CEC473629" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_CA42C1E08BE00106B3295F1CEC47DD09_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_CA42C1E08BE00106B3295F1CEC47DD09" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_5FDE7DB67ED8B25D06685F1CEC473629" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_CA42C1E08BE00106B3295F1CEC47DD09" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertibleDebtMember" xlink:label="loc_us-gaap_ConvertibleDebtMember_A14EB2D5CB4D30380EC75F1CEC47D9E3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_CA42C1E08BE00106B3295F1CEC47DD09" xlink:to="loc_us-gaap_ConvertibleDebtMember_A14EB2D5CB4D30380EC75F1CEC47D9E3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember" xlink:label="loc_us-gaap_LineOfCreditMember_3E747E187B91054D524B5F1CEC48FD26" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_CA42C1E08BE00106B3295F1CEC47DD09" xlink:to="loc_us-gaap_LineOfCreditMember_3E747E187B91054D524B5F1CEC48FD26" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_BD872207371D8F4C44D65F1CEC484B8B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_800A309D8E1C34F1FB055F1CEC443628" xlink:to="loc_us-gaap_VariableRateAxis_BD872207371D8F4C44D65F1CEC484B8B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_B6AD1763A8C088B398E75F1CEC4843B6_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_BD872207371D8F4C44D65F1CEC484B8B" xlink:to="loc_us-gaap_VariableRateDomain_B6AD1763A8C088B398E75F1CEC4843B6_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_B6AD1763A8C088B398E75F1CEC4843B6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_BD872207371D8F4C44D65F1CEC484B8B" xlink:to="loc_us-gaap_VariableRateDomain_B6AD1763A8C088B398E75F1CEC4843B6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_CDC1A4744033B9DB1AB05F1CEC4897DA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_B6AD1763A8C088B398E75F1CEC4843B6" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_CDC1A4744033B9DB1AB05F1CEC4897DA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_680ECD6DD4E1CED5D0515F1CEC49A856" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_800A309D8E1C34F1FB055F1CEC443628" xlink:to="loc_srt_RangeAxis_680ECD6DD4E1CED5D0515F1CEC49A856" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_374A4D98485B5DEEAD485F1CEC494A8E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_680ECD6DD4E1CED5D0515F1CEC49A856" xlink:to="loc_srt_RangeMember_374A4D98485B5DEEAD485F1CEC494A8E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_374A4D98485B5DEEAD485F1CEC494A8E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_680ECD6DD4E1CED5D0515F1CEC49A856" xlink:to="loc_srt_RangeMember_374A4D98485B5DEEAD485F1CEC494A8E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_B2D0188B3BF2390ABF295F1CEC4ECB0D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_374A4D98485B5DEEAD485F1CEC494A8E" xlink:to="loc_srt_MinimumMember_B2D0188B3BF2390ABF295F1CEC4ECB0D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_8772BB0E654E77BBD5775F1CEC4F87ED" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_374A4D98485B5DEEAD485F1CEC494A8E" xlink:to="loc_srt_MaximumMember_8772BB0E654E77BBD5775F1CEC4F87ED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_DA9E6BCA32B93D4A59985F1CEC4FD1E1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_DA9E6BCA32B93D4A59985F1CEC4FD1E1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_A08E5355CD2CBD33CB4C5F1CEC4FA8CB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_A08E5355CD2CBD33CB4C5F1CEC4FA8CB" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DebtInstrumentConvertibleIncrementalPrincipalAmountConvertible" xlink:label="loc_otex_DebtInstrumentConvertibleIncrementalPrincipalAmountConvertible_158FB53D1AEDCC3434265F1CEC5018B3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_otex_DebtInstrumentConvertibleIncrementalPrincipalAmountConvertible_158FB53D1AEDCC3434265F1CEC5018B3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_E9A5C2D1090CE3BB7EC85F1CEC50137E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_E9A5C2D1090CE3BB7EC85F1CEC50137E" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DebtInstrumentConvertibleConversionRateIncreaseDecrease" xlink:label="loc_otex_DebtInstrumentConvertibleConversionRateIncreaseDecrease_F9832D0BAF32449616285F1CEC50BFE5" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_otex_DebtInstrumentConvertibleConversionRateIncreaseDecrease_F9832D0BAF32449616285F1CEC50BFE5" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DebtInstrumentConvertibleConversionRate" xlink:label="loc_otex_DebtInstrumentConvertibleConversionRate_EBE75E9D7D806B68C0535F1CEC50F7B1" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_otex_DebtInstrumentConvertibleConversionRate_EBE75E9D7D806B68C0535F1CEC50F7B1" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DebtInstrumentConvertibleIfconvertedValueperThousandDollarsofPrincipal" xlink:label="loc_otex_DebtInstrumentConvertibleIfconvertedValueperThousandDollarsofPrincipal_CFA719CE4D17556520335F1CEC5110BE" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_otex_DebtInstrumentConvertibleIfconvertedValueperThousandDollarsofPrincipal_CFA719CE4D17556520335F1CEC5110BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_D1BCB4E1BB28EA2789895F1CEC51B10E" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_D1BCB4E1BB28EA2789895F1CEC51B10E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromIssuanceOfDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfDebt_C93D5E62B3E052B153D45F1CEC5147AF" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfDebt_C93D5E62B3E052B153D45F1CEC5147AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTerm" xlink:label="loc_us-gaap_DebtInstrumentTerm_449037DD75A1DF5D1C885F1CEC511776" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_DebtInstrumentTerm_449037DD75A1DF5D1C885F1CEC511776" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DebtInstrumentPeriodicPaymentQuarterlyRepaymentPercentageofPrincipal" xlink:label="loc_otex_DebtInstrumentPeriodicPaymentQuarterlyRepaymentPercentageofPrincipal_3C158D2EE3302C7A0EC75F1CEC528EF4" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_otex_DebtInstrumentPeriodicPaymentQuarterlyRepaymentPercentageofPrincipal_3C158D2EE3302C7A0EC75F1CEC528EF4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_E54E93108B8649B39C135F1CEC52682D" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_E54E93108B8649B39C135F1CEC52682D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_DFCB9D8B138FEFBB749E5F1CEC52BD69" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_DFCB9D8B138FEFBB749E5F1CEC52BD69" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DebtInstrumentCovenantLeverageRatioMaximum" xlink:label="loc_otex_DebtInstrumentCovenantLeverageRatioMaximum_67F1D08AECF64C99C42A5F1CEC52449E" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_otex_DebtInstrumentCovenantLeverageRatioMaximum_67F1D08AECF64C99C42A5F1CEC52449E" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DebtInstrumentLeverageRatio" xlink:label="loc_otex_DebtInstrumentLeverageRatio_A2FDAFC9C3108295C6485F1CEC526DA0" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_otex_DebtInstrumentLeverageRatio_A2FDAFC9C3108295C6485F1CEC526DA0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpenseDebt" xlink:label="loc_us-gaap_InterestExpenseDebt_1CBFEC6BEC813DDBF2695F1CEC52C361" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_InterestExpenseDebt_1CBFEC6BEC813DDBF2695F1CEC52C361" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_2B1C79A7D44F45CFE2F85F1CEC533A0A" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_2B1C79A7D44F45CFE2F85F1CEC533A0A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_74A34129647731054FBB5F1CEC53D7C1" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_74A34129647731054FBB5F1CEC53D7C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RepaymentsOfDebt" xlink:label="loc_us-gaap_RepaymentsOfDebt_15D33ADB93CCCA3F49E55F1CEC53F388" xlink:type="locator" />
    <link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_RepaymentsOfDebt_15D33ADB93CCCA3F49E55F1CEC53F388" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_891D42F4D91C34DB184E5F1CEC531822" xlink:type="locator" />
    <link:definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1C782FF9CC1327F0E30A5F1CEC4FF495" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_891D42F4D91C34DB184E5F1CEC531822" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/LongTermDebtScheduleOfLongTermDebtDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_745838CB26B02E1D4C095F1CEFD7E149" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_6BBDC023F6DA1D7BCF7B5F1CEFCDF229" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_745838CB26B02E1D4C095F1CEFD7E149" xlink:to="loc_us-gaap_DebtInstrumentTable_6BBDC023F6DA1D7BCF7B5F1CEFCDF229" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_D6D064FD9736E8183F835F1CEFCD6AAE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6BBDC023F6DA1D7BCF7B5F1CEFCDF229" xlink:to="loc_us-gaap_CreditFacilityAxis_D6D064FD9736E8183F835F1CEFCD6AAE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_45CAEEF85FA4EC1799AE5F1CEFCEB522_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_D6D064FD9736E8183F835F1CEFCD6AAE" xlink:to="loc_us-gaap_CreditFacilityDomain_45CAEEF85FA4EC1799AE5F1CEFCEB522_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_45CAEEF85FA4EC1799AE5F1CEFCEB522" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_D6D064FD9736E8183F835F1CEFCD6AAE" xlink:to="loc_us-gaap_CreditFacilityDomain_45CAEEF85FA4EC1799AE5F1CEFCEB522" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_8941DACF1B105E800E5A5F1CEFCE8B9A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_45CAEEF85FA4EC1799AE5F1CEFCEB522" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_8941DACF1B105E800E5A5F1CEFCE8B9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_D855D43D3BE776AA08F35F1CEFCE9B46" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6BBDC023F6DA1D7BCF7B5F1CEFCDF229" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_D855D43D3BE776AA08F35F1CEFCE9B46" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_BABCB57A077A7EC7F9DB5F1CEFCF0921_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_D855D43D3BE776AA08F35F1CEFCE9B46" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_BABCB57A077A7EC7F9DB5F1CEFCF0921_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_BABCB57A077A7EC7F9DB5F1CEFCF0921" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_D855D43D3BE776AA08F35F1CEFCE9B46" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_BABCB57A077A7EC7F9DB5F1CEFCF0921" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_5295503840C2E744A57C5F1CEFCFCDE5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_BABCB57A077A7EC7F9DB5F1CEFCF0921" xlink:to="loc_us-gaap_SeniorNotesMember_5295503840C2E744A57C5F1CEFCFCDE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember" xlink:label="loc_us-gaap_LineOfCreditMember_692582D46BD2EF510E2E5F1CEFCF71A6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_BABCB57A077A7EC7F9DB5F1CEFCF0921" xlink:to="loc_us-gaap_LineOfCreditMember_692582D46BD2EF510E2E5F1CEFCF71A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_9310504E3B13CC3035245F1CEFD022F5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_6BBDC023F6DA1D7BCF7B5F1CEFCDF229" xlink:to="loc_us-gaap_DebtInstrumentAxis_9310504E3B13CC3035245F1CEFD022F5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_F8068651D1738F3EF44B5F1CEFD0EA86_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_9310504E3B13CC3035245F1CEFD022F5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_F8068651D1738F3EF44B5F1CEFD0EA86_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_F8068651D1738F3EF44B5F1CEFD0EA86" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_9310504E3B13CC3035245F1CEFD022F5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_F8068651D1738F3EF44B5F1CEFD0EA86" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SeniorNotes2030Member" xlink:label="loc_otex_SeniorNotes2030Member_015BE6CB7D5176E4B1865F1CEFD0ACAB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F8068651D1738F3EF44B5F1CEFD0EA86" xlink:to="loc_otex_SeniorNotes2030Member_015BE6CB7D5176E4B1865F1CEFD0ACAB" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SeniorNotes2028Member" xlink:label="loc_otex_SeniorNotes2028Member_0909603D339F337657095F1CEFD00B8A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F8068651D1738F3EF44B5F1CEFD0EA86" xlink:to="loc_otex_SeniorNotes2028Member_0909603D339F337657095F1CEFD00B8A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SeniorNotes2026Member" xlink:label="loc_otex_SeniorNotes2026Member_4B276B626AB0BA48A6355F1CEFD1B11B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F8068651D1738F3EF44B5F1CEFD0EA86" xlink:to="loc_otex_SeniorNotes2026Member_4B276B626AB0BA48A6355F1CEFD1B11B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SeniorNotes2023Member" xlink:label="loc_otex_SeniorNotes2023Member_3780E5D26541618BC4895F1CEFD6E871" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F8068651D1738F3EF44B5F1CEFD0EA86" xlink:to="loc_otex_SeniorNotes2023Member_3780E5D26541618BC4895F1CEFD6E871" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_TermLoanBMember" xlink:label="loc_otex_TermLoanBMember_F236CF802F3E0D1478975F1CEFD67D48" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F8068651D1738F3EF44B5F1CEFD0EA86" xlink:to="loc_otex_TermLoanBMember_F236CF802F3E0D1478975F1CEFD67D48" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_651FB75BE6EC2F03CB6D5F1CEFD72A34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_745838CB26B02E1D4C095F1CEFD7E149" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_651FB75BE6EC2F03CB6D5F1CEFD72A34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentUnamortizedPremium" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedPremium_C58012D937AF0FEBC31C5F1CEFD77F15" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_745838CB26B02E1D4C095F1CEFD7E149" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedPremium_C58012D937AF0FEBC31C5F1CEFD77F15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_72AFE5B53087900676845F1CEFD7050F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_745838CB26B02E1D4C095F1CEFD7E149" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_72AFE5B53087900676845F1CEFD7050F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebt" xlink:label="loc_us-gaap_LongTermDebt_94D39ED45F784805E9985F1CEFD80817" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_745838CB26B02E1D4C095F1CEFD7E149" xlink:to="loc_us-gaap_LongTermDebt_94D39ED45F784805E9985F1CEFD80817" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtCurrentAndNoncurrentAbstract" xlink:label="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_A83536D73EF6815593DA5F1CEFD8B1A0" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_745838CB26B02E1D4C095F1CEFD7E149" xlink:to="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_A83536D73EF6815593DA5F1CEFD8B1A0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="loc_us-gaap_LongTermDebtCurrent_C93AED860EEB296D20F65F1CEFD87843" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_A83536D73EF6815593DA5F1CEFD8B1A0" xlink:to="loc_us-gaap_LongTermDebtCurrent_C93AED860EEB296D20F65F1CEFD87843" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_6E35B7B68CC44F3DFC8F5F1CEFD8E74C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_745838CB26B02E1D4C095F1CEFD7E149" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_6E35B7B68CC44F3DFC8F5F1CEFD8E74C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/LongTermDebtSeniorUnsecuredFixedRateNotesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_FA46C8726F4C211C91E85F1CF0183C7F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_8D17A9664E0F9375E5705F1CF0116C63" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FA46C8726F4C211C91E85F1CF0183C7F" xlink:to="loc_us-gaap_DebtInstrumentTable_8D17A9664E0F9375E5705F1CF0116C63" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_0ECFF91276075C7051785F1CF011C529" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_8D17A9664E0F9375E5705F1CF0116C63" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_0ECFF91276075C7051785F1CF011C529" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_4C12DCEC7C39AF249BA15F1CF0117A25_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0ECFF91276075C7051785F1CF011C529" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_4C12DCEC7C39AF249BA15F1CF0117A25_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_4C12DCEC7C39AF249BA15F1CF0117A25" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0ECFF91276075C7051785F1CF011C529" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_4C12DCEC7C39AF249BA15F1CF0117A25" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_E1ECE43DB979931E731B5F1CF01127AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4C12DCEC7C39AF249BA15F1CF0117A25" xlink:to="loc_us-gaap_SeniorNotesMember_E1ECE43DB979931E731B5F1CF01127AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_49AE5E9AB4779776245F5F1CF012C7D2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_8D17A9664E0F9375E5705F1CF0116C63" xlink:to="loc_us-gaap_DebtInstrumentAxis_49AE5E9AB4779776245F5F1CF012C7D2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4BC5A4799CAE3DC2DED45F1CF0128805_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_49AE5E9AB4779776245F5F1CF012C7D2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4BC5A4799CAE3DC2DED45F1CF0128805_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4BC5A4799CAE3DC2DED45F1CF0128805" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_49AE5E9AB4779776245F5F1CF012C7D2" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4BC5A4799CAE3DC2DED45F1CF0128805" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SeniorNotes2030Member" xlink:label="loc_otex_SeniorNotes2030Member_DEDB1271974ED72D83B95F1CF012EC39" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4BC5A4799CAE3DC2DED45F1CF0128805" xlink:to="loc_otex_SeniorNotes2030Member_DEDB1271974ED72D83B95F1CF012EC39" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SeniorNotes2028Member" xlink:label="loc_otex_SeniorNotes2028Member_C5345939915366AEDF595F1CF0135C87" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4BC5A4799CAE3DC2DED45F1CF0128805" xlink:to="loc_otex_SeniorNotes2028Member_C5345939915366AEDF595F1CF0135C87" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SeniorNotes2026Member" xlink:label="loc_otex_SeniorNotes2026Member_BE320571D07246A457235F1CF01300E1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4BC5A4799CAE3DC2DED45F1CF0128805" xlink:to="loc_otex_SeniorNotes2026Member_BE320571D07246A457235F1CF01300E1" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SeniorNotes2023Member" xlink:label="loc_otex_SeniorNotes2023Member_7192AB8E9E3BC05224975F1CF018F673" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4BC5A4799CAE3DC2DED45F1CF0128805" xlink:to="loc_otex_SeniorNotes2023Member_7192AB8E9E3BC05224975F1CF018F673" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_BFDE72B45BFD4D5F45655F1CF0197F30" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FA46C8726F4C211C91E85F1CF0183C7F" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_BFDE72B45BFD4D5F45655F1CF0197F30" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_2C2588F3EB28A50410B15F1CF01994A4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FA46C8726F4C211C91E85F1CF0183C7F" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_2C2588F3EB28A50410B15F1CF01994A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpenseDebt" xlink:label="loc_us-gaap_InterestExpenseDebt_3CCFD443621DBBB0F6035F1CF0194083" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FA46C8726F4C211C91E85F1CF0183C7F" xlink:to="loc_us-gaap_InterestExpenseDebt_3CCFD443621DBBB0F6035F1CF0194083" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DebtInstrumentIssuancePricePercentageofFaceValue" xlink:label="loc_otex_DebtInstrumentIssuancePricePercentageofFaceValue_C79F9F66384C0E0FF5C05F1CF01AB496" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FA46C8726F4C211C91E85F1CF0183C7F" xlink:to="loc_otex_DebtInstrumentIssuancePricePercentageofFaceValue_C79F9F66384C0E0FF5C05F1CF01AB496" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_4E2664ADB4F6EFD8ECD25F1CF01A0A28" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FA46C8726F4C211C91E85F1CF0183C7F" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_4E2664ADB4F6EFD8ECD25F1CF01A0A28" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed_754AD264E9F086CAF0985F1CF01A96CA" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FA46C8726F4C211C91E85F1CF0183C7F" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed_754AD264E9F086CAF0985F1CF01A96CA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_06C41F0207F16FC513AF5F1CF01A8C68" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_FA46C8726F4C211C91E85F1CF0183C7F" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_06C41F0207F16FC513AF5F1CF01A8C68" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/LongTermDebtTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/OtherAssets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/OtherAssetsAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_6461C47EE9CA833FFC2C5F1CEEFEA2D2" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_478F55DC5EDF3F90C7B55F1CEEFCEB08" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_6461C47EE9CA833FFC2C5F1CEEFEA2D2" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_478F55DC5EDF3F90C7B55F1CEEFCEB08" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_5DB2E68276ADE6930B405F1CEEFC4354" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_478F55DC5EDF3F90C7B55F1CEEFCEB08" xlink:to="loc_srt_RangeAxis_5DB2E68276ADE6930B405F1CEEFC4354" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_32FF52C957737F7ACDE15F1CEEFD0BDD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_5DB2E68276ADE6930B405F1CEEFC4354" xlink:to="loc_srt_RangeMember_32FF52C957737F7ACDE15F1CEEFD0BDD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_32FF52C957737F7ACDE15F1CEEFD0BDD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_5DB2E68276ADE6930B405F1CEEFC4354" xlink:to="loc_srt_RangeMember_32FF52C957737F7ACDE15F1CEEFD0BDD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_214D808F6B76AB25A7905F1CEEFDFE56" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_32FF52C957737F7ACDE15F1CEEFD0BDD" xlink:to="loc_srt_MinimumMember_214D808F6B76AB25A7905F1CEEFDFE56" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_10EF7EDE0B3227975C835F1CEEFDF9E5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_32FF52C957737F7ACDE15F1CEEFD0BDD" xlink:to="loc_srt_MaximumMember_10EF7EDE0B3227975C835F1CEEFDF9E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_015A5261A2F555B875205F1CEEFE8405" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_6461C47EE9CA833FFC2C5F1CEEFEA2D2" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_015A5261A2F555B875205F1CEEFE8405" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/OtherAssetsScheduleDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/OtherAssetsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/OtherIncomeExpenseNet" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/OtherIncomeExpenseNetAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_A1E15CE0D2E9D532969C5F1CF3738F5A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_1DB86E48E8CDBBAD7BBE5F1CF371B261" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A1E15CE0D2E9D532969C5F1CF3738F5A" xlink:to="loc_us-gaap_DebtInstrumentTable_1DB86E48E8CDBBAD7BBE5F1CF371B261" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_ED1005C11F54DDDF1C7C5F1CF3723B8A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1DB86E48E8CDBBAD7BBE5F1CF371B261" xlink:to="loc_us-gaap_DebtInstrumentAxis_ED1005C11F54DDDF1C7C5F1CF3723B8A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4A5B4CE817E00A76EC635F1CF372BD43_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_ED1005C11F54DDDF1C7C5F1CF3723B8A" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4A5B4CE817E00A76EC635F1CF372BD43_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4A5B4CE817E00A76EC635F1CF372BD43" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_ED1005C11F54DDDF1C7C5F1CF3723B8A" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4A5B4CE817E00A76EC635F1CF372BD43" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SeniorNotes2023Member" xlink:label="loc_otex_SeniorNotes2023Member_CDCF5696F5AFC3D14C965F1CF372F60E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4A5B4CE817E00A76EC635F1CF372BD43" xlink:to="loc_otex_SeniorNotes2023Member_CDCF5696F5AFC3D14C965F1CF372F60E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_AC9E538205BEDBB46E845F1CF3737AC4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1DB86E48E8CDBBAD7BBE5F1CF371B261" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_AC9E538205BEDBB46E845F1CF3737AC4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_53C5BDF12CC3C2571B725F1CF3731CC2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_AC9E538205BEDBB46E845F1CF3737AC4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_53C5BDF12CC3C2571B725F1CF3731CC2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_53C5BDF12CC3C2571B725F1CF3731CC2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_AC9E538205BEDBB46E845F1CF3737AC4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_53C5BDF12CC3C2571B725F1CF3731CC2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_9A09CDAB6EB0F650F95A5F1CF3733315" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_53C5BDF12CC3C2571B725F1CF3731CC2" xlink:to="loc_us-gaap_SeniorNotesMember_9A09CDAB6EB0F650F95A5F1CF3733315" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_5A7F68215DFE1F234AD55F1CF374139E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A1E15CE0D2E9D532969C5F1CF3738F5A" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_5A7F68215DFE1F234AD55F1CF374139E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_A6676CA4884E32F8F38C5F1CF374A799" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A1E15CE0D2E9D532969C5F1CF3738F5A" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_A6676CA4884E32F8F38C5F1CF374A799" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost_FD7275D6192DF1662F6A5F1CF374490D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_A1E15CE0D2E9D532969C5F1CF3738F5A" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost_FD7275D6192DF1662F6A5F1CF374490D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/OtherIncomeExpenseNetScheduleOfOtherIncomeExpenseNetDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/OtherIncomeExpenseNetTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefits" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_E44E6C1EB277A3762B3D5F1CEAF75423" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_421BA5D70F1BFEB275FF5F1CEAF2F763" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_E44E6C1EB277A3762B3D5F1CEAF75423" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_421BA5D70F1BFEB275FF5F1CEAF2F763" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_9B9BDB6B5661C74EC7695F1CEAF29E90" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_421BA5D70F1BFEB275FF5F1CEAF2F763" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_9B9BDB6B5661C74EC7695F1CEAF29E90" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_0D932DBB4BB16DB9CC2F5F1CEAF33A73_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_9B9BDB6B5661C74EC7695F1CEAF29E90" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_0D932DBB4BB16DB9CC2F5F1CEAF33A73_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_0D932DBB4BB16DB9CC2F5F1CEAF33A73" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_9B9BDB6B5661C74EC7695F1CEAF29E90" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_0D932DBB4BB16DB9CC2F5F1CEAF33A73" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_DA6A2F87B3DAD75DA4B15F1CEAF4233F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_0D932DBB4BB16DB9CC2F5F1CEAF33A73" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_DA6A2F87B3DAD75DA4B15F1CEAF4233F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="loc_us-gaap_RetirementPlanNameAxis_66BCBF7E3FF8E3E259D85F1CEAF5676A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_421BA5D70F1BFEB275FF5F1CEAF2F763" xlink:to="loc_us-gaap_RetirementPlanNameAxis_66BCBF7E3FF8E3E259D85F1CEAF5676A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_9171AD5CDD584E4A3F385F1CEAF5F913_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanNameAxis_66BCBF7E3FF8E3E259D85F1CEAF5676A" xlink:to="loc_us-gaap_RetirementPlanNameDomain_9171AD5CDD584E4A3F385F1CEAF5F913_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_9171AD5CDD584E4A3F385F1CEAF5F913" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanNameAxis_66BCBF7E3FF8E3E259D85F1CEAF5676A" xlink:to="loc_us-gaap_RetirementPlanNameDomain_9171AD5CDD584E4A3F385F1CEAF5F913" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CDTMember" xlink:label="loc_otex_CDTMember_0004B7DAE85A5736231B5F1CEAF5AC61" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_9171AD5CDD584E4A3F385F1CEAF5F913" xlink:to="loc_otex_CDTMember_0004B7DAE85A5736231B5F1CEAF5AC61" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSGermanyMember" xlink:label="loc_otex_GXSGermanyMember_C48A14340E4A9BD3CB995F1CEAF606A4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_9171AD5CDD584E4A3F385F1CEAF5F913" xlink:to="loc_otex_GXSGermanyMember_C48A14340E4A9BD3CB995F1CEAF606A4" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSPhilippineMember" xlink:label="loc_otex_GXSPhilippineMember_FAF97E200DEA414639995F1CEAF6D01D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_9171AD5CDD584E4A3F385F1CEAF5F913" xlink:to="loc_otex_GXSPhilippineMember_FAF97E200DEA414639995F1CEAF6D01D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_84C2ED785417CCB893EB5F1CEAF7421B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_E44E6C1EB277A3762B3D5F1CEAF75423" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_84C2ED785417CCB893EB5F1CEAF7421B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear_741BE460A3E1418AF9D65F1CEAF77764" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_E44E6C1EB277A3762B3D5F1CEAF75423" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear_741BE460A3E1418AF9D65F1CEAF77764" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_5CF169691449A35353BD5F1CEAF72309" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_E44E6C1EB277A3762B3D5F1CEAF75423" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_5CF169691449A35353BD5F1CEAF72309" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsAnticipatedPensionPaymentsUnderPensionPlansDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_89B4072F83D647D1E0405F1CEF70DCF5" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9A18D08436717B3C640F5F1CEF6D46CD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_89B4072F83D647D1E0405F1CEF70DCF5" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9A18D08436717B3C640F5F1CEF6D46CD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_E24B7D54801605C98F9B5F1CEF6D8C18" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9A18D08436717B3C640F5F1CEF6D46CD" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_E24B7D54801605C98F9B5F1CEF6D8C18" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_A965183F8E327CA590445F1CEF6EBDD9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_E24B7D54801605C98F9B5F1CEF6D8C18" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_A965183F8E327CA590445F1CEF6EBDD9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_A965183F8E327CA590445F1CEF6EBDD9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_E24B7D54801605C98F9B5F1CEF6D8C18" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_A965183F8E327CA590445F1CEF6EBDD9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_B00520011EA817EDA1145F1CEF6E6132" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_A965183F8E327CA590445F1CEF6EBDD9" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_B00520011EA817EDA1145F1CEF6E6132" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="loc_us-gaap_RetirementPlanNameAxis_F4322E34FDF6DA68451A5F1CEF6E6262" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9A18D08436717B3C640F5F1CEF6D46CD" xlink:to="loc_us-gaap_RetirementPlanNameAxis_F4322E34FDF6DA68451A5F1CEF6E6262" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_50FE5D0CB235195D4F4E5F1CEF6EC864_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanNameAxis_F4322E34FDF6DA68451A5F1CEF6E6262" xlink:to="loc_us-gaap_RetirementPlanNameDomain_50FE5D0CB235195D4F4E5F1CEF6EC864_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_50FE5D0CB235195D4F4E5F1CEF6EC864" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanNameAxis_F4322E34FDF6DA68451A5F1CEF6E6262" xlink:to="loc_us-gaap_RetirementPlanNameDomain_50FE5D0CB235195D4F4E5F1CEF6EC864" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CDTMember" xlink:label="loc_otex_CDTMember_54F84E4B188F75EFAF2E5F1CEF6F7B46" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_50FE5D0CB235195D4F4E5F1CEF6EC864" xlink:to="loc_otex_CDTMember_54F84E4B188F75EFAF2E5F1CEF6F7B46" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSGermanyMember" xlink:label="loc_otex_GXSGermanyMember_0AB5FAD9C12ADD8BC1AC5F1CEF6F41C1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_50FE5D0CB235195D4F4E5F1CEF6EC864" xlink:to="loc_otex_GXSGermanyMember_0AB5FAD9C12ADD8BC1AC5F1CEF6F41C1" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSPhilippineMember" xlink:label="loc_otex_GXSPhilippineMember_3379DEFA5093187181AC5F1CEF6F899A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_50FE5D0CB235195D4F4E5F1CEF6EC864" xlink:to="loc_otex_GXSPhilippineMember_3379DEFA5093187181AC5F1CEF6F899A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_187D16E21397F1819BA15F1CEF7020D1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_89B4072F83D647D1E0405F1CEF70DCF5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_187D16E21397F1819BA15F1CEF7020D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_5BF14AA1538CEC50597C5F1CEF706638" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_89B4072F83D647D1E0405F1CEF70DCF5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_5BF14AA1538CEC50597C5F1CEF706638" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_7896516CA7C5048907FC5F1CEF70AA15" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_89B4072F83D647D1E0405F1CEF70DCF5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_7896516CA7C5048907FC5F1CEF70AA15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_E7115457D6A388BB44035F1CEF70C4D0" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_89B4072F83D647D1E0405F1CEF70DCF5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_E7115457D6A388BB44035F1CEF70C4D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_6A0450BFE1EAAE985C2E5F1CEF715B95" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_89B4072F83D647D1E0405F1CEF70DCF5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_6A0450BFE1EAAE985C2E5F1CEF715B95" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_7CA34EBB404047099A1E5F1CEF71899C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_89B4072F83D647D1E0405F1CEF70DCF5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_7CA34EBB404047099A1E5F1CEF71899C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DefinedBenefitPlanExpectedFutureBenefitPaymentsTotal" xlink:label="loc_otex_DefinedBenefitPlanExpectedFutureBenefitPaymentsTotal_5507E76C3C568EF5FA785F1CEF71AAE1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_89B4072F83D647D1E0405F1CEF70DCF5" xlink:to="loc_otex_DefinedBenefitPlanExpectedFutureBenefitPaymentsTotal_5507E76C3C568EF5FA785F1CEF71AAE1" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsComponentsOfNetPensionExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0AA8961A9ABD7A151E55F25D36E242E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0CCF550F4A85AA21723B5F25D36CDA36" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0AA8961A9ABD7A151E55F25D36E242E" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0CCF550F4A85AA21723B5F25D36CDA36" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_3D6BC01E094B7B3E19695F25D36C07D9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0CCF550F4A85AA21723B5F25D36CDA36" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_3D6BC01E094B7B3E19695F25D36C07D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_9B990C45209825F43FC95F25D36C8CB3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_3D6BC01E094B7B3E19695F25D36C07D9" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_9B990C45209825F43FC95F25D36C8CB3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_9B990C45209825F43FC95F25D36C8CB3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_3D6BC01E094B7B3E19695F25D36C07D9" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_9B990C45209825F43FC95F25D36C8CB3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_329E569B1711E4705FBB5F25D36D33FF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_9B990C45209825F43FC95F25D36C8CB3" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_329E569B1711E4705FBB5F25D36D33FF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="loc_us-gaap_RetirementPlanNameAxis_900FA7BA4EFD775708895F25D36D9483" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0CCF550F4A85AA21723B5F25D36CDA36" xlink:to="loc_us-gaap_RetirementPlanNameAxis_900FA7BA4EFD775708895F25D36D9483" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_1B6910E503C82F0639B55F25D36D328E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanNameAxis_900FA7BA4EFD775708895F25D36D9483" xlink:to="loc_us-gaap_RetirementPlanNameDomain_1B6910E503C82F0639B55F25D36D328E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_1B6910E503C82F0639B55F25D36D328E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanNameAxis_900FA7BA4EFD775708895F25D36D9483" xlink:to="loc_us-gaap_RetirementPlanNameDomain_1B6910E503C82F0639B55F25D36D328E" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CDTMember" xlink:label="loc_otex_CDTMember_6A78BC48178AA99A68295F25D36D047E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_1B6910E503C82F0639B55F25D36D328E" xlink:to="loc_otex_CDTMember_6A78BC48178AA99A68295F25D36D047E" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSGermanyMember" xlink:label="loc_otex_GXSGermanyMember_BF0184A91DFA72718D105F25D36E6F1A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_1B6910E503C82F0639B55F25D36D328E" xlink:to="loc_otex_GXSGermanyMember_BF0184A91DFA72718D105F25D36E6F1A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSPhilippineMember" xlink:label="loc_otex_GXSPhilippineMember_1A9140EA37587CFA44CA5F25D36E735A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_1B6910E503C82F0639B55F25D36D328E" xlink:to="loc_otex_GXSPhilippineMember_1A9140EA37587CFA44CA5F25D36E735A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_CBC9C329A03B99018C515F25D36E7CDA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0AA8961A9ABD7A151E55F25D36E242E" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_CBC9C329A03B99018C515F25D36E7CDA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_2950A350961E06B751195F25D36F2707" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0AA8961A9ABD7A151E55F25D36E242E" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_2950A350961E06B751195F25D36F2707" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_9882893E63C53103176E5F25D36F0331" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0AA8961A9ABD7A151E55F25D36E242E" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_9882893E63C53103176E5F25D36F0331" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionExpense" xlink:label="loc_us-gaap_PensionExpense_ABD9262A39FEA91FDFDB5F25D36FC624" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0AA8961A9ABD7A151E55F25D36E242E" xlink:to="loc_us-gaap_PensionExpense_ABD9262A39FEA91FDFDB5F25D36FC624" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleList" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleList_58E5A65D9B61E81468D45F56EE81A8A1" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0AA8961A9ABD7A151E55F25D36E242E" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleList_58E5A65D9B61E81468D45F56EE81A8A1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditAmortizationOfGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleList" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditAmortizationOfGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleList_9962CC8507D9EDA4CA655F585C5E83DA" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0AA8961A9ABD7A151E55F25D36E242E" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditAmortizationOfGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleList_9962CC8507D9EDA4CA655F585C5E83DA" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsScheduleOfChangeInBenefitObligationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_99F89AB25EC2495BC9085F1CF24F7CBE" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_45F47F8387FDC4F4B1DE5F1CF24D891A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_99F89AB25EC2495BC9085F1CF24F7CBE" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_45F47F8387FDC4F4B1DE5F1CF24D891A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_A667EA99542591D5F3545F1CF24D1DDF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_45F47F8387FDC4F4B1DE5F1CF24D891A" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_A667EA99542591D5F3545F1CF24D1DDF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_B85E2887017CB9C0041C5F1CF24D77EA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_A667EA99542591D5F3545F1CF24D1DDF" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_B85E2887017CB9C0041C5F1CF24D77EA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_B85E2887017CB9C0041C5F1CF24D77EA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_A667EA99542591D5F3545F1CF24D1DDF" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_B85E2887017CB9C0041C5F1CF24D77EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_1CF0574CA920C3FBD0D25F1CF24EF408" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_B85E2887017CB9C0041C5F1CF24D77EA" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_1CF0574CA920C3FBD0D25F1CF24EF408" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="loc_us-gaap_RetirementPlanNameAxis_D7153619DEDB62F7ADC35F1CF24EAB1C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_45F47F8387FDC4F4B1DE5F1CF24D891A" xlink:to="loc_us-gaap_RetirementPlanNameAxis_D7153619DEDB62F7ADC35F1CF24EAB1C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_09A51C14BF738102A5DF5F1CF24E7C4E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanNameAxis_D7153619DEDB62F7ADC35F1CF24EAB1C" xlink:to="loc_us-gaap_RetirementPlanNameDomain_09A51C14BF738102A5DF5F1CF24E7C4E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_09A51C14BF738102A5DF5F1CF24E7C4E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanNameAxis_D7153619DEDB62F7ADC35F1CF24EAB1C" xlink:to="loc_us-gaap_RetirementPlanNameDomain_09A51C14BF738102A5DF5F1CF24E7C4E" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CDTMember" xlink:label="loc_otex_CDTMember_78C2A4453A012EFDBAD45F1CF24F0537" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_09A51C14BF738102A5DF5F1CF24E7C4E" xlink:to="loc_otex_CDTMember_78C2A4453A012EFDBAD45F1CF24F0537" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSGermanyMember" xlink:label="loc_otex_GXSGermanyMember_32564DB57007A9C339CF5F1CF24F93A2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_09A51C14BF738102A5DF5F1CF24E7C4E" xlink:to="loc_otex_GXSGermanyMember_32564DB57007A9C339CF5F1CF24F93A2" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSPhilippineMember" xlink:label="loc_otex_GXSPhilippineMember_6D083ACEF80ADA47AC105F1CF24FEB20" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_09A51C14BF738102A5DF5F1CF24E7C4E" xlink:to="loc_otex_GXSPhilippineMember_6D083ACEF80ADA47AC105F1CF24FEB20" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_99F89AB25EC2495BC9085F1CF24F7CBE" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_A99C2421EB1C9683D3B05F1CF250C828" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_A99C2421EB1C9683D3B05F1CF250C828" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_59C9E5A96510C5B930205F1CF2518E74" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_59C9E5A96510C5B930205F1CF2518E74" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_BE35384FFC77278360455F1CF2517AAA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_BE35384FFC77278360455F1CF2517AAA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_B5C6B66EF1682E58B53C5F1CF2516EC5" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_B5C6B66EF1682E58B53C5F1CF2516EC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_DF1641F8417EC0C749645F1CF2515D08" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_DF1641F8417EC0C749645F1CF2515D08" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_49276DF344C3FE2A87AA5F1CF2514B86" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:to="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_49276DF344C3FE2A87AA5F1CF2514B86" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPensionPlanLiabilitiesCurrent" xlink:label="loc_us-gaap_DefinedBenefitPensionPlanLiabilitiesCurrent_D83DEBD8BCA1A9231C545F1CF2527CA3" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:to="loc_us-gaap_DefinedBenefitPensionPlanLiabilitiesCurrent_D83DEBD8BCA1A9231C545F1CF2527CA3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent" xlink:label="loc_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent_09A9C11C19AC1C15058E5F1CF2524A1D" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_99E90231A372A25F18AD5F1CF250B713" xlink:to="loc_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent_09A9C11C19AC1C15058E5F1CF2524A1D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsScheduleOfDefinedBenefitPlansAndLongTermEmployeeBenefitObligationsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_524428A16CFD3F79CE8C5F1CF3048CFB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_610C0C3B414A145FB0EC5F1CF301330E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_524428A16CFD3F79CE8C5F1CF3048CFB" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_610C0C3B414A145FB0EC5F1CF301330E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_FD0832EEA40E13E2DD0A5F1CF301DC9D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_610C0C3B414A145FB0EC5F1CF301330E" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_FD0832EEA40E13E2DD0A5F1CF301DC9D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_B9330454000A56BEE6485F1CF30104E9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_FD0832EEA40E13E2DD0A5F1CF301DC9D" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_B9330454000A56BEE6485F1CF30104E9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_B9330454000A56BEE6485F1CF30104E9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_FD0832EEA40E13E2DD0A5F1CF301DC9D" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_B9330454000A56BEE6485F1CF30104E9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_6D6BE17EFA1EAEAD40A15F1CF302BE0D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_B9330454000A56BEE6485F1CF30104E9" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_6D6BE17EFA1EAEAD40A15F1CF302BE0D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_314F2ED2459D363D06A35F1CF3024684" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_B9330454000A56BEE6485F1CF30104E9" xlink:to="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_314F2ED2459D363D06A35F1CF3024684" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="loc_us-gaap_RetirementPlanNameAxis_5B2B87573A005D67FA005F1CF30259F6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_610C0C3B414A145FB0EC5F1CF301330E" xlink:to="loc_us-gaap_RetirementPlanNameAxis_5B2B87573A005D67FA005F1CF30259F6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_FAD861853961684BBE7A5F1CF302AD91_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanNameAxis_5B2B87573A005D67FA005F1CF30259F6" xlink:to="loc_us-gaap_RetirementPlanNameDomain_FAD861853961684BBE7A5F1CF302AD91_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_FAD861853961684BBE7A5F1CF302AD91" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanNameAxis_5B2B87573A005D67FA005F1CF30259F6" xlink:to="loc_us-gaap_RetirementPlanNameDomain_FAD861853961684BBE7A5F1CF302AD91" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CDTMember" xlink:label="loc_otex_CDTMember_7886C27165920F27D84F5F1CF30369C8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_FAD861853961684BBE7A5F1CF302AD91" xlink:to="loc_otex_CDTMember_7886C27165920F27D84F5F1CF30369C8" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSGermanyMember" xlink:label="loc_otex_GXSGermanyMember_0A688009AE47D74AC9875F1CF30396D0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_FAD861853961684BBE7A5F1CF302AD91" xlink:to="loc_otex_GXSGermanyMember_0A688009AE47D74AC9875F1CF30396D0" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSPhilippineMember" xlink:label="loc_otex_GXSPhilippineMember_7F02ED24BA49335808095F1CF3043A33" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_FAD861853961684BBE7A5F1CF302AD91" xlink:to="loc_otex_GXSPhilippineMember_7F02ED24BA49335808095F1CF3043A33" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent_840B96E94203DFFB8C4A5F1CF3041318" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_524428A16CFD3F79CE8C5F1CF3048CFB" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent_840B96E94203DFFB8C4A5F1CF3041318" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_90EBF526C4CAB6DA94CD5F1CF3047CAE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_524428A16CFD3F79CE8C5F1CF3048CFB" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_90EBF526C4CAB6DA94CD5F1CF3047CAE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_A7CF37A50A53F79C99CC5F1CF304B05A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_524428A16CFD3F79CE8C5F1CF3048CFB" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_A7CF37A50A53F79C99CC5F1CF304B05A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsScheduleOfWeightedAverageKeyAssumptionsUsedForPensionPlansDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0C629C4D7001144086E4A70C6881EA0F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0887CF5F2F47AB6D4997A70C687A76DA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0C629C4D7001144086E4A70C6881EA0F" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0887CF5F2F47AB6D4997A70C687A76DA" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_E33E16854F2CDE30D670A70C687B755D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0887CF5F2F47AB6D4997A70C687A76DA" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_E33E16854F2CDE30D670A70C687B755D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_649B61BF8643E211DE16A70C687B8316_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_E33E16854F2CDE30D670A70C687B755D" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_649B61BF8643E211DE16A70C687B8316_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_649B61BF8643E211DE16A70C687B8316" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_E33E16854F2CDE30D670A70C687B755D" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_649B61BF8643E211DE16A70C687B8316" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_CD064AC0B5B4720AF27BA70C687C60CD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_649B61BF8643E211DE16A70C687B8316" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_CD064AC0B5B4720AF27BA70C687C60CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="loc_us-gaap_RetirementPlanNameAxis_0B1A11BD1332382A7395A70C687C9844" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0887CF5F2F47AB6D4997A70C687A76DA" xlink:to="loc_us-gaap_RetirementPlanNameAxis_0B1A11BD1332382A7395A70C687C9844" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_8D89C1F50FFBCDFBC461A70C687C103B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanNameAxis_0B1A11BD1332382A7395A70C687C9844" xlink:to="loc_us-gaap_RetirementPlanNameDomain_8D89C1F50FFBCDFBC461A70C687C103B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="loc_us-gaap_RetirementPlanNameDomain_8D89C1F50FFBCDFBC461A70C687C103B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanNameAxis_0B1A11BD1332382A7395A70C687C9844" xlink:to="loc_us-gaap_RetirementPlanNameDomain_8D89C1F50FFBCDFBC461A70C687C103B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CDTMember" xlink:label="loc_otex_CDTMember_218A402C37DC19679312A70C687DE60B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_8D89C1F50FFBCDFBC461A70C687C103B" xlink:to="loc_otex_CDTMember_218A402C37DC19679312A70C687DE60B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSGermanyMember" xlink:label="loc_otex_GXSGermanyMember_EE049251A254784352EAA70C687DB9B4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_8D89C1F50FFBCDFBC461A70C687C103B" xlink:to="loc_otex_GXSGermanyMember_EE049251A254784352EAA70C687DB9B4" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_GXSPhilippineMember" xlink:label="loc_otex_GXSPhilippineMember_086F9F919941DDBAA33DA70C687DEFF8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanNameDomain_8D89C1F50FFBCDFBC461A70C687C103B" xlink:to="loc_otex_GXSPhilippineMember_086F9F919941DDBAA33DA70C687DEFF8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_C5398DFD31689079C0F5A70C687D0871" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0887CF5F2F47AB6D4997A70C687A76DA" xlink:to="loc_srt_RangeAxis_C5398DFD31689079C0F5A70C687D0871" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_FC6D44332BF76F036471A70C687EE33A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_C5398DFD31689079C0F5A70C687D0871" xlink:to="loc_srt_RangeMember_FC6D44332BF76F036471A70C687EE33A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_FC6D44332BF76F036471A70C687EE33A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_C5398DFD31689079C0F5A70C687D0871" xlink:to="loc_srt_RangeMember_FC6D44332BF76F036471A70C687EE33A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_9FE19A9B52FAE89AF21BA70C687EF618" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_FC6D44332BF76F036471A70C687EE33A" xlink:to="loc_srt_MinimumMember_9FE19A9B52FAE89AF21BA70C687EF618" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_78932E9E815C52A07E5AA70C687EF46A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_FC6D44332BF76F036471A70C687EE33A" xlink:to="loc_srt_MaximumMember_78932E9E815C52A07E5AA70C687EF46A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DefinedBenefitPlanEmployeeAgeGroupAxis" xlink:label="loc_otex_DefinedBenefitPlanEmployeeAgeGroupAxis_FBE47513A35CDA018E51A70C687FCFD5" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0887CF5F2F47AB6D4997A70C687A76DA" xlink:to="loc_otex_DefinedBenefitPlanEmployeeAgeGroupAxis_FBE47513A35CDA018E51A70C687FCFD5" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DefinedBenefitPlanEmployeeAgeGroupDomain" xlink:label="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupAxis_FBE47513A35CDA018E51A70C687FCFD5" xlink:to="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958_default" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DefinedBenefitPlanEmployeeAgeGroupDomain" xlink:label="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupAxis_FBE47513A35CDA018E51A70C687FCFD5" xlink:to="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EmployeeAgeUpto20Member" xlink:label="loc_otex_EmployeeAgeUpto20Member_E96ACC0D5B62EAF1C221A70C6880AD60" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:to="loc_otex_EmployeeAgeUpto20Member_E96ACC0D5B62EAF1C221A70C6880AD60" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EmployeeAgeUpto25Member" xlink:label="loc_otex_EmployeeAgeUpto25Member_6893E3E63A83FA6792F9A70C68803843" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:to="loc_otex_EmployeeAgeUpto25Member_6893E3E63A83FA6792F9A70C68803843" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EmployeeAgeUpToThirtyMember" xlink:label="loc_otex_EmployeeAgeUpToThirtyMember_FA0EC303BE55180CB935A70C68807B2C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:to="loc_otex_EmployeeAgeUpToThirtyMember_FA0EC303BE55180CB935A70C68807B2C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EmployeeAgeUpToThirtyFiveMember" xlink:label="loc_otex_EmployeeAgeUpToThirtyFiveMember_7E2242C214C39D804A80A70C6881037A" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:to="loc_otex_EmployeeAgeUpToThirtyFiveMember_7E2242C214C39D804A80A70C6881037A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EmployeeAgeUpToFortyMember" xlink:label="loc_otex_EmployeeAgeUpToFortyMember_2444F63ED8C1C1DDA523A70C6881C579" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:to="loc_otex_EmployeeAgeUpToFortyMember_2444F63ED8C1C1DDA523A70C6881C579" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EmployeeAgeUpToFortyFiveMember" xlink:label="loc_otex_EmployeeAgeUpToFortyFiveMember_4E53BFFED4663A55E1D5A70C6881BF62" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:to="loc_otex_EmployeeAgeUpToFortyFiveMember_4E53BFFED4663A55E1D5A70C6881BF62" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EmployeeAgeUpToFiftyMember" xlink:label="loc_otex_EmployeeAgeUpToFiftyMember_F0D2509A8B8AA2BEDE65A70C6881191F" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:to="loc_otex_EmployeeAgeUpToFiftyMember_F0D2509A8B8AA2BEDE65A70C6881191F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EmployeeAgeAboveFiftyOneMember" xlink:label="loc_otex_EmployeeAgeAboveFiftyOneMember_EA26B9DE1155B9093005A70C68818018" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_DefinedBenefitPlanEmployeeAgeGroupDomain_62DDAB7032DD839EBA67A70C687F7958" xlink:to="loc_otex_EmployeeAgeAboveFiftyOneMember_EA26B9DE1155B9093005A70C68818018" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease_E21D3D0A7A145D63FB62A70C6882C09C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0C629C4D7001144086E4A70C6881EA0F" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease_E21D3D0A7A145D63FB62A70C6882C09C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfPensionIncrease" xlink:label="loc_otex_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfPensionIncrease_C81FD0503D5CBC7525E6A70C6882BDC1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0C629C4D7001144086E4A70C6881EA0F" xlink:to="loc_otex_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfPensionIncrease_C81FD0503D5CBC7525E6A70C6882BDC1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_164B3C170A562763FE93A70C68820209" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0C629C4D7001144086E4A70C6881EA0F" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_164B3C170A562763FE93A70C68820209" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRetirementAge" xlink:label="loc_otex_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRetirementAge_3F0CD7A9CA96BC37D1A7A70C68834C3F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0C629C4D7001144086E4A70C6881EA0F" xlink:to="loc_otex_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRetirementAge_3F0CD7A9CA96BC37D1A7A70C68834C3F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_EmployeeFluctuationRate" xlink:label="loc_otex_EmployeeFluctuationRate_D3B93610D2D5E7E54E64A70C6883C5FE" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0C629C4D7001144086E4A70C6881EA0F" xlink:to="loc_otex_EmployeeFluctuationRate_D3B93610D2D5E7E54E64A70C6883C5FE" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/PensionPlansAndOtherPostRetirementBenefitsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/PropertyAndEquipment" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/PropertyAndEquipmentDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_645EB87C7BDA5AA65BC45F1CF35528AB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_E3C7C288B3C08776D40D5F1CF351B6BE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_645EB87C7BDA5AA65BC45F1CF35528AB" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_E3C7C288B3C08776D40D5F1CF351B6BE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7EA170779A3B86F649065F1CF35225B5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_E3C7C288B3C08776D40D5F1CF351B6BE" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7EA170779A3B86F649065F1CF35225B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7EA170779A3B86F649065F1CF35225B5" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7EA170779A3B86F649065F1CF35225B5" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_B100A84B21222F36E0AB5F1CF3537249" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_B100A84B21222F36E0AB5F1CF3537249" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OfficeEquipmentMember" xlink:label="loc_us-gaap_OfficeEquipmentMember_AEE5ECD2DA2E525A6D4B5F1CF353F670" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1" xlink:to="loc_us-gaap_OfficeEquipmentMember_AEE5ECD2DA2E525A6D4B5F1CF353F670" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ComputerHardwareMember" xlink:label="loc_otex_ComputerHardwareMember_1D3C22885372411E45C05F1CF3532E3C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1" xlink:to="loc_otex_ComputerHardwareMember_1D3C22885372411E45C05F1CF3532E3C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ComputerSoftwareMember" xlink:label="loc_otex_ComputerSoftwareMember_3AC157B37A0BF74F8C0C5F1CF354F3C7" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1" xlink:to="loc_otex_ComputerSoftwareMember_3AC157B37A0BF74F8C0C5F1CF354F3C7" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CapitalizedSoftwareMember" xlink:label="loc_otex_CapitalizedSoftwareMember_3982CB74DA0B6C4B44ED5F1CF3543F55" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1" xlink:to="loc_otex_CapitalizedSoftwareMember_3982CB74DA0B6C4B44ED5F1CF3543F55" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_B9096AA85FF80D15DA9B5F1CF354016D" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_B9096AA85FF80D15DA9B5F1CF354016D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_1E866BD4F0DC2C5D36F75F1CF354EB30" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_E8D64582795F1F00EE4C5F1CF3528DE1" xlink:to="loc_us-gaap_BuildingMember_1E866BD4F0DC2C5D36F75F1CF354EB30" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_ED323B62C2B94184790D5F1CF355DBD3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_645EB87C7BDA5AA65BC45F1CF35528AB" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_ED323B62C2B94184790D5F1CF355DBD3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_0ABC23BA234D8B75F22B5F1CF3557459" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_645EB87C7BDA5AA65BC45F1CF35528AB" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_0ABC23BA234D8B75F22B5F1CF3557459" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_243688E7633CF6AF44E45F1CF355A3B5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_645EB87C7BDA5AA65BC45F1CF35528AB" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_243688E7633CF6AF44E45F1CF355A3B5" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/PropertyAndEquipmentTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/RelatedPartyTransactions" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/RelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_B0904DCB2F2C489BCCE75F1CF2E857C2" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_26DF09199F6EE6DA6E9B5F1CF2E6025C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_B0904DCB2F2C489BCCE75F1CF2E857C2" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_26DF09199F6EE6DA6E9B5F1CF2E6025C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_803D6CEF9B6DDF2198365F1CF2E74899" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_26DF09199F6EE6DA6E9B5F1CF2E6025C" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_803D6CEF9B6DDF2198365F1CF2E74899" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_A94410EFAAD3E7C087705F1CF2E78639_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_803D6CEF9B6DDF2198365F1CF2E74899" xlink:to="loc_us-gaap_RelatedPartyDomain_A94410EFAAD3E7C087705F1CF2E78639_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_A94410EFAAD3E7C087705F1CF2E78639" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_803D6CEF9B6DDF2198365F1CF2E74899" xlink:to="loc_us-gaap_RelatedPartyDomain_A94410EFAAD3E7C087705F1CF2E78639" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_DirectorMember" xlink:label="loc_srt_DirectorMember_49E90E46B72D2A72CDCF5F1CF2E7E003" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_A94410EFAAD3E7C087705F1CF2E78639" xlink:to="loc_srt_DirectorMember_49E90E46B72D2A72CDCF5F1CF2E7E003" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProfessionalFees" xlink:label="loc_us-gaap_ProfessionalFees_12A1A7C2A5820FA0240B5F1CF2E8E469" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_B0904DCB2F2C489BCCE75F1CF2E857C2" xlink:to="loc_us-gaap_ProfessionalFees_12A1A7C2A5820FA0240B5F1CF2E8E469" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/Revenues" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/RevenuesContractBalancesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/RevenuesDisaggregationOfRevenueDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_EC960C65CD466D1A9EE15F1CF22203ED" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_9046FB8FFF544EDD937C5F1CF218A016" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_EC960C65CD466D1A9EE15F1CF22203ED" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_9046FB8FFF544EDD937C5F1CF218A016" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_5A9E4F9B73EC8A035E7E5F1CF2198D46" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_9046FB8FFF544EDD937C5F1CF218A016" xlink:to="loc_srt_StatementGeographicalAxis_5A9E4F9B73EC8A035E7E5F1CF2198D46" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_5529C5BEBDE5CB50E6C25F1CF219E183_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_5A9E4F9B73EC8A035E7E5F1CF2198D46" xlink:to="loc_srt_SegmentGeographicalDomain_5529C5BEBDE5CB50E6C25F1CF219E183_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_5529C5BEBDE5CB50E6C25F1CF219E183" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_5A9E4F9B73EC8A035E7E5F1CF2198D46" xlink:to="loc_srt_SegmentGeographicalDomain_5529C5BEBDE5CB50E6C25F1CF219E183" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_AmericasMember" xlink:label="loc_srt_AmericasMember_51D63BEE6EF5D8E727495F1CF2190DE4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5529C5BEBDE5CB50E6C25F1CF219E183" xlink:to="loc_srt_AmericasMember_51D63BEE6EF5D8E727495F1CF2190DE4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EMEAMember" xlink:label="loc_us-gaap_EMEAMember_16E40C091F61D23006B85F1CF21A51F6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5529C5BEBDE5CB50E6C25F1CF219E183" xlink:to="loc_us-gaap_EMEAMember_16E40C091F61D23006B85F1CF21A51F6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_AsiaPacificMember" xlink:label="loc_srt_AsiaPacificMember_D650453222321AA21D2B5F1CF21ACB8C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5529C5BEBDE5CB50E6C25F1CF219E183" xlink:to="loc_srt_AsiaPacificMember_D650453222321AA21D2B5F1CF21ACB8C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srt_ProductOrServiceAxis_1CB4FA35A9EE9685A2D85F1CF21AF9C8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_9046FB8FFF544EDD937C5F1CF218A016" xlink:to="loc_srt_ProductOrServiceAxis_1CB4FA35A9EE9685A2D85F1CF21AF9C8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_8BA0C3FED36ABB0FCDFD5F1CF21A533C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_1CB4FA35A9EE9685A2D85F1CF21AF9C8" xlink:to="loc_srt_ProductsAndServicesDomain_8BA0C3FED36ABB0FCDFD5F1CF21A533C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srt_ProductsAndServicesDomain_8BA0C3FED36ABB0FCDFD5F1CF21A533C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_1CB4FA35A9EE9685A2D85F1CF21AF9C8" xlink:to="loc_srt_ProductsAndServicesDomain_8BA0C3FED36ABB0FCDFD5F1CF21A533C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CloudRevenuesAndCustomerSupportRevenuesMember" xlink:label="loc_otex_CloudRevenuesAndCustomerSupportRevenuesMember_83B14ED6C5D2224E43265F1CF21BBE47" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8BA0C3FED36ABB0FCDFD5F1CF21A533C" xlink:to="loc_otex_CloudRevenuesAndCustomerSupportRevenuesMember_83B14ED6C5D2224E43265F1CF21BBE47" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CloudServicesAndSubscriptionsMember" xlink:label="loc_otex_CloudServicesAndSubscriptionsMember_5DD3FADAB31D032295F15F1CF21BE144" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_CloudRevenuesAndCustomerSupportRevenuesMember_83B14ED6C5D2224E43265F1CF21BBE47" xlink:to="loc_otex_CloudServicesAndSubscriptionsMember_5DD3FADAB31D032295F15F1CF21BE144" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CustomerSupportMember" xlink:label="loc_otex_CustomerSupportMember_82E820E29BFB67158CDC5F1CF21B1D04" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_CloudRevenuesAndCustomerSupportRevenuesMember_83B14ED6C5D2224E43265F1CF21BBE47" xlink:to="loc_otex_CustomerSupportMember_82E820E29BFB67158CDC5F1CF21B1D04" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LicenseMember" xlink:label="loc_us-gaap_LicenseMember_9755B911E8098F8B448F5F1CF21B0015" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8BA0C3FED36ABB0FCDFD5F1CF21A533C" xlink:to="loc_us-gaap_LicenseMember_9755B911E8098F8B448F5F1CF21B0015" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ProfessionalServiceAndOtherMember" xlink:label="loc_otex_ProfessionalServiceAndOtherMember_AAE70E09FCF5B90B14035F1CF221C833" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_8BA0C3FED36ABB0FCDFD5F1CF21A533C" xlink:to="loc_otex_ProfessionalServiceAndOtherMember_AAE70E09FCF5B90B14035F1CF221C833" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceAxis" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_498E750D78B74E2AF3585F1CF2217B90" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_9046FB8FFF544EDD937C5F1CF218A016" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_498E750D78B74E2AF3585F1CF2217B90" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_B7A903EA8FDEDD17EFB05F1CF2210997_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_498E750D78B74E2AF3585F1CF2217B90" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_B7A903EA8FDEDD17EFB05F1CF2210997_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_B7A903EA8FDEDD17EFB05F1CF2210997" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_498E750D78B74E2AF3585F1CF2217B90" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_B7A903EA8FDEDD17EFB05F1CF2210997" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TransferredAtPointInTimeMember" xlink:label="loc_us-gaap_TransferredAtPointInTimeMember_F634BC7774FD7C46BDD45F1CF2226281" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_B7A903EA8FDEDD17EFB05F1CF2210997" xlink:to="loc_us-gaap_TransferredAtPointInTimeMember_F634BC7774FD7C46BDD45F1CF2226281" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TransferredOverTimeMember" xlink:label="loc_us-gaap_TransferredOverTimeMember_153D8E3DA173A710B8D55F1CF2225FCE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_B7A903EA8FDEDD17EFB05F1CF2210997" xlink:to="loc_us-gaap_TransferredOverTimeMember_153D8E3DA173A710B8D55F1CF2225FCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_DEB0340D2E6BD409BC545F1CF2236EB7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_EC960C65CD466D1A9EE15F1CF22203ED" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_DEB0340D2E6BD409BC545F1CF2236EB7" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/RevenuesIncrementalCostsOfObtainingContractWithCustomerDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/RevenuesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/RevenuesTransactionPriceAllocatedToRemainingPerformanceObligationsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_CFF764E44DC23DA80A7F5F1CF147EB49" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_D984AB7A6E0B369411115F1CF146353F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_CFF764E44DC23DA80A7F5F1CF147EB49" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_D984AB7A6E0B369411115F1CF146353F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_3FBAEB8C31D4DBA9E6D75F1CF146E41E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_D984AB7A6E0B369411115F1CF146353F" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_3FBAEB8C31D4DBA9E6D75F1CF146E41E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_11F3F42BDFF5071251315F1CF1475F38" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_CFF764E44DC23DA80A7F5F1CF147EB49" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_11F3F42BDFF5071251315F1CF1475F38" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_C7AD1D8479659869BDD55F1CF1477E53" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_CFF764E44DC23DA80A7F5F1CF147EB49" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_C7AD1D8479659869BDD55F1CF1477E53" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_1666AAB080E6939AE8135F1CF147EE4C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_CFF764E44DC23DA80A7F5F1CF147EB49" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_1666AAB080E6939AE8135F1CF147EE4C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/SegmentInformation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/SegmentInformationAdditionalInformationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/SegmentInformationEntityWideDisclosureOnGeographicAreasLongLivedAssetsInIndividualForeignCountriesByCountryDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_40FA30CED65740A3FC8BA0D793936AD4" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_59EB48E17E1F62A21006A0D7938CFC31" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_40FA30CED65740A3FC8BA0D793936AD4" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_59EB48E17E1F62A21006A0D7938CFC31" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_0492AD04B71C251ABB8FA0D7938CFC79" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_59EB48E17E1F62A21006A0D7938CFC31" xlink:to="loc_srt_StatementGeographicalAxis_0492AD04B71C251ABB8FA0D7938CFC79" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_0492AD04B71C251ABB8FA0D7938CFC79" xlink:to="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_0492AD04B71C251ABB8FA0D7938CFC79" xlink:to="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_CA" xlink:label="loc_country_CA_8A0276C80431CA8E9F43A0D7938DE0CC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B" xlink:to="loc_country_CA_8A0276C80431CA8E9F43A0D7938DE0CC" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_9D15453800084845C3B4A0D79392ED1B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B" xlink:to="loc_country_US_9D15453800084845C3B4A0D79392ED1B" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_GB" xlink:label="loc_country_GB_BAEB474852C53FEAFEB5A0D79393D016" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B" xlink:to="loc_country_GB_BAEB474852C53FEAFEB5A0D79393D016" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_DE" xlink:label="loc_country_DE_B2424E283E98426A9A18A0D79393134B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B" xlink:to="loc_country_DE_B2424E283E98426A9A18A0D79393134B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_RestofEMEAMember" xlink:label="loc_otex_RestofEMEAMember_3343CCA1FDBDFB1BFA8EA119E642CCA1" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B" xlink:to="loc_otex_RestofEMEAMember_3343CCA1FDBDFB1BFA8EA119E642CCA1" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_AllOtherCountriesMember" xlink:label="loc_otex_AllOtherCountriesMember_D91A9313798B866B04F7A0D79393D0B5" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_B904840F6636827229AEA0D7938D902B" xlink:to="loc_otex_AllOtherCountriesMember_D91A9313798B866B04F7A0D79393D0B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncurrentAssets" xlink:label="loc_us-gaap_NoncurrentAssets_5AB2037D8E57619C4977A0D79394E2CC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_40FA30CED65740A3FC8BA0D793936AD4" xlink:to="loc_us-gaap_NoncurrentAssets_5AB2037D8E57619C4977A0D79394E2CC" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/SegmentInformationRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_7B1501ABFD797305B80F7327DFD7758A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1A448CA8D44400F09FF47327DFCF8F74" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_7B1501ABFD797305B80F7327DFD7758A" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1A448CA8D44400F09FF47327DFCF8F74" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srt_StatementGeographicalAxis_FEBACA9149676FED04377327DFD06485" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1A448CA8D44400F09FF47327DFCF8F74" xlink:to="loc_srt_StatementGeographicalAxis_FEBACA9149676FED04377327DFD06485" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_FEBACA9149676FED04377327DFD06485" xlink:to="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_FEBACA9149676FED04377327DFD06485" xlink:to="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_CA" xlink:label="loc_country_CA_2E89919209407F1C7D127327DFD54D0C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914" xlink:to="loc_country_CA_2E89919209407F1C7D127327DFD54D0C" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US" xlink:label="loc_country_US_EB0BE89B62A41648014B7327DFD6C74C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914" xlink:to="loc_country_US_EB0BE89B62A41648014B7327DFD6C74C" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_GB" xlink:label="loc_country_GB_E015B4CDA494980C845D7327DFD6CFB9" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914" xlink:to="loc_country_GB_E015B4CDA494980C845D7327DFD6CFB9" xlink:type="arc" />
    <link:loc xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_DE" xlink:label="loc_country_DE_137142DEE0F1F44987657327DFD65763" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914" xlink:to="loc_country_DE_137142DEE0F1F44987657327DFD65763" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_RestofEMEAMember" xlink:label="loc_otex_RestofEMEAMember_66AB671CCAF2467B57F273322EF2369F" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914" xlink:to="loc_otex_RestofEMEAMember_66AB671CCAF2467B57F273322EF2369F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_AllOtherCountriesMember" xlink:label="loc_otex_AllOtherCountriesMember_20DEA1A0D635791F51337327DFD60F00" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_D435D75C0232EBCE98247327DFD5B914" xlink:to="loc_otex_AllOtherCountriesMember_20DEA1A0D635791F51337327DFD60F00" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_C4DE93981CA1F1179A087327DFD7DE7E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_7B1501ABFD797305B80F7327DFD7758A" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_C4DE93981CA1F1179A087327DFD7DE7E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/SegmentInformationTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPayments" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsAdditionalInformationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsLongTermIncentivePlansDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_48A3E43913D702ABF5365F1CF32E3B52" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F6E448B8DF41B339D0DC5F1CF32DCDBF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_48A3E43913D702ABF5365F1CF32E3B52" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F6E448B8DF41B339D0DC5F1CF32DCDBF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_9E8FB118E3A2A06F858F5F1CF32DCA71" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F6E448B8DF41B339D0DC5F1CF32DCDBF" xlink:to="loc_us-gaap_PlanNameAxis_9E8FB118E3A2A06F858F5F1CF32DCA71" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_FDCBFE7D9A048157719E5F1CF32E0570_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_9E8FB118E3A2A06F858F5F1CF32DCA71" xlink:to="loc_us-gaap_PlanNameDomain_FDCBFE7D9A048157719E5F1CF32E0570_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_FDCBFE7D9A048157719E5F1CF32E0570" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_9E8FB118E3A2A06F858F5F1CF32DCA71" xlink:to="loc_us-gaap_PlanNameDomain_FDCBFE7D9A048157719E5F1CF32E0570" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_LongTermIncentivePlanMember" xlink:label="loc_otex_LongTermIncentivePlanMember_F2C3D11FEAA60F3161605F1CF32E2377" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_FDCBFE7D9A048157719E5F1CF32E0570" xlink:to="loc_otex_LongTermIncentivePlanMember_F2C3D11FEAA60F3161605F1CF32E2377" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2019LongtermIncentivePlanMember" xlink:label="loc_otex_Fiscal2019LongtermIncentivePlanMember_85CDBD38FDCE2C2CB3DC5F1CF32EA236" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_FDCBFE7D9A048157719E5F1CF32E0570" xlink:to="loc_otex_Fiscal2019LongtermIncentivePlanMember_85CDBD38FDCE2C2CB3DC5F1CF32EA236" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_81D72E3CFC27A5D644845F1CF32EFCFD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_48A3E43913D702ABF5365F1CF32E3B52" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_81D72E3CFC27A5D644845F1CF32EFCFD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_09B4FFD4C84E4A72F25E5F1CF32F2ABE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_48A3E43913D702ABF5365F1CF32E3B52" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_09B4FFD4C84E4A72F25E5F1CF32F2ABE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_B6ED8B658E36021192F35F1CF32F883E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_48A3E43913D702ABF5365F1CF32E3B52" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_B6ED8B658E36021192F35F1CF32F883E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued_DCA6FEF49E0A4251234E5F1CF32FB9C2" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_48A3E43913D702ABF5365F1CF32E3B52" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued_DCA6FEF49E0A4251234E5F1CF32FB9C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_75495519A5C160336D615F1CF32F923E" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_48A3E43913D702ABF5365F1CF32E3B52" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_75495519A5C160336D615F1CF32F923E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsRsusDsusAndEsppDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C009C4B3954510F53E465F1CF337DD7B" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_C17C44915E8494855DFF5F1CF335A075" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C009C4B3954510F53E465F1CF337DD7B" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_C17C44915E8494855DFF5F1CF335A075" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_4A38B7F659540CDC1E7D5F1CF33566CE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_C17C44915E8494855DFF5F1CF335A075" xlink:to="loc_us-gaap_AwardTypeAxis_4A38B7F659540CDC1E7D5F1CF33566CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D8B0B2398E9E9713C9925F1CF33603D0_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_4A38B7F659540CDC1E7D5F1CF33566CE" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D8B0B2398E9E9713C9925F1CF33603D0_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D8B0B2398E9E9713C9925F1CF33603D0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_4A38B7F659540CDC1E7D5F1CF33566CE" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D8B0B2398E9E9713C9925F1CF33603D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_2D3560DC56109827201A5F1CF336E598" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D8B0B2398E9E9713C9925F1CF33603D0" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_2D3560DC56109827201A5F1CF336E598" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DeferredStockUnitsMember" xlink:label="loc_otex_DeferredStockUnitsMember_E891495C937C7E1863A35F1CF3369B2F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D8B0B2398E9E9713C9925F1CF33603D0" xlink:to="loc_otex_DeferredStockUnitsMember_E891495C937C7E1863A35F1CF3369B2F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockMember" xlink:label="loc_us-gaap_EmployeeStockMember_B36C6643DEEC8B8932065F1CF337D7A0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_D8B0B2398E9E9713C9925F1CF33603D0" xlink:to="loc_us-gaap_EmployeeStockMember_B36C6643DEEC8B8932065F1CF337D7A0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_0D2238AF3033BD620B7B5F1CF3378615" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C009C4B3954510F53E465F1CF337DD7B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_0D2238AF3033BD620B7B5F1CF3378615" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_EDE0BFC40F269C131AD35F1CF337DE1B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C009C4B3954510F53E465F1CF337DD7B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_EDE0BFC40F269C131AD35F1CF337DE1B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_02190B20A554314F85F25F1CF3387458" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C009C4B3954510F53E465F1CF337DD7B" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_02190B20A554314F85F25F1CF3387458" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_6D4C6A9B140FA64A3C425F1CF3382A34" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C009C4B3954510F53E465F1CF337DD7B" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_6D4C6A9B140FA64A3C425F1CF3382A34" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SharebasedCompensationArrangementbySharebasedPaymentAwardPurchasePriceDiscount" xlink:label="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardPurchasePriceDiscount_F0C6589C235D5EE57BB15F1CF338B085" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C009C4B3954510F53E465F1CF337DD7B" xlink:to="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardPurchasePriceDiscount_F0C6589C235D5EE57BB15F1CF338B085" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SharebasedCompensationArrangementbySharebasedPaymentAwardSharesEligibleforIssuance" xlink:label="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardSharesEligibleforIssuance_DEF31D4323AD8482B29D5F1CF338480A" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C009C4B3954510F53E465F1CF337DD7B" xlink:to="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardSharesEligibleforIssuance_DEF31D4323AD8482B29D5F1CF338480A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_CashReceivedFromEmployeeStockPurchasePlan" xlink:label="loc_otex_CashReceivedFromEmployeeStockPurchasePlan_8905B704DD9DF64918F95F1CF3387F37" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C009C4B3954510F53E465F1CF337DD7B" xlink:to="loc_otex_CashReceivedFromEmployeeStockPurchasePlan_8905B704DD9DF64918F95F1CF3387F37" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsScheduleOfOutstandingStockOptionsActivityDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsScheduleOfShareBasedPaymentsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4AF9D4A3CC89979D13295F1CF30E7B63" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D59A0CFE62C4A8A55A085F1CF30B2920" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4AF9D4A3CC89979D13295F1CF30E7B63" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D59A0CFE62C4A8A55A085F1CF30B2920" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_60BEE60D8399F18A67695F1CF30BE91F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D59A0CFE62C4A8A55A085F1CF30B2920" xlink:to="loc_us-gaap_AwardTypeAxis_60BEE60D8399F18A67695F1CF30BE91F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_197DA1E9F93890F653615F1CF30B17B4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_60BEE60D8399F18A67695F1CF30BE91F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_197DA1E9F93890F653615F1CF30B17B4_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_197DA1E9F93890F653615F1CF30B17B4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_60BEE60D8399F18A67695F1CF30BE91F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_197DA1E9F93890F653615F1CF30B17B4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_77E9F5E57942648A0FBC5F1CF30B6ADF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_197DA1E9F93890F653615F1CF30B17B4" xlink:to="loc_us-gaap_EmployeeStockOptionMember_77E9F5E57942648A0FBC5F1CF30B6ADF" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_PerformanceStockUnitsMember" xlink:label="loc_otex_PerformanceStockUnitsMember_DF155AA2E49880A451655F1CF30C076E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_197DA1E9F93890F653615F1CF30B17B4" xlink:to="loc_otex_PerformanceStockUnitsMember_DF155AA2E49880A451655F1CF30C076E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_8A65B521341D8C4D68B85F1CF30CEE8E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_197DA1E9F93890F653615F1CF30B17B4" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_8A65B521341D8C4D68B85F1CF30CEE8E" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_DeferredStockUnitsMember" xlink:label="loc_otex_DeferredStockUnitsMember_719E9E73A9C225827F7F5F1CF30C122F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_197DA1E9F93890F653615F1CF30B17B4" xlink:to="loc_otex_DeferredStockUnitsMember_719E9E73A9C225827F7F5F1CF30C122F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockMember" xlink:label="loc_us-gaap_EmployeeStockMember_CE42DFE4EDAE7A9ECBD25F1CF30D0C13" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_197DA1E9F93890F653615F1CF30B17B4" xlink:to="loc_us-gaap_EmployeeStockMember_CE42DFE4EDAE7A9ECBD25F1CF30D0C13" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_BE315842DC5A4A7816CF5F1CF30DE5A6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D59A0CFE62C4A8A55A085F1CF30B2920" xlink:to="loc_us-gaap_PlanNameAxis_BE315842DC5A4A7816CF5F1CF30DE5A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_6325F6F913D7159082505F1CF30DB100_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_BE315842DC5A4A7816CF5F1CF30DE5A6" xlink:to="loc_us-gaap_PlanNameDomain_6325F6F913D7159082505F1CF30DB100_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_6325F6F913D7159082505F1CF30DB100" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_BE315842DC5A4A7816CF5F1CF30DE5A6" xlink:to="loc_us-gaap_PlanNameDomain_6325F6F913D7159082505F1CF30DB100" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_LongTermIncentivePlanMember" xlink:label="loc_otex_LongTermIncentivePlanMember_204690D50D5200F5DDAD5F1CF30DB032" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_6325F6F913D7159082505F1CF30DB100" xlink:to="loc_otex_LongTermIncentivePlanMember_204690D50D5200F5DDAD5F1CF30DB032" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_OtherPlansMember" xlink:label="loc_otex_OtherPlansMember_331D100594E54A0F7E165F1CF30DCCB1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_6325F6F913D7159082505F1CF30DB100" xlink:to="loc_otex_OtherPlansMember_331D100594E54A0F7E165F1CF30DCCB1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_1F19DF7AB4208FFDEB035F1CF30ED493" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4AF9D4A3CC89979D13295F1CF30E7B63" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_1F19DF7AB4208FFDEB035F1CF30ED493" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsScheduleOfWeightedAverageFairValueOfOptionsAndWeightedAverageAssumptionsUsedDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsSummaryOfInformationRegardingStockOptionsOutstandingDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7763284785D686BFC6015F1CEB653098" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D7D477EE466AB63CB3445F1CEB61D12B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7763284785D686BFC6015F1CEB653098" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D7D477EE466AB63CB3445F1CEB61D12B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_AAE3ED0FDE733A5BD7775F1CEB617BAC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_D7D477EE466AB63CB3445F1CEB61D12B" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_AAE3ED0FDE733A5BD7775F1CEB617BAC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_AAE3ED0FDE733A5BD7775F1CEB617BAC" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_AAE3ED0FDE733A5BD7775F1CEB617BAC" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeOneMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeOneMember_C6C1A4D48C9C9C34D0B75F1CEB62314C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeOneMember_C6C1A4D48C9C9C34D0B75F1CEB62314C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeTwoMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeTwoMember_CFF942593C92796425D15F1CEB62D91C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeTwoMember_CFF942593C92796425D15F1CEB62D91C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeThreeMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeThreeMember_0D049FD802D3C93C94BD5F1CEB6388D7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeThreeMember_0D049FD802D3C93C94BD5F1CEB6388D7" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeFourMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeFourMember_CADCB66C8F4EB6270D5E5F1CEB6341E1" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeFourMember_CADCB66C8F4EB6270D5E5F1CEB6341E1" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeFiveMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeFiveMember_69AB4B836CAD0291383C5F1CEB63AE2A" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeFiveMember_69AB4B836CAD0291383C5F1CEB63AE2A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeSixMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeSixMember_C3FE6DC878E2E5B5AB705F1CEB632271" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeSixMember_C3FE6DC878E2E5B5AB705F1CEB632271" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeSevenMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeSevenMember_F2A88815DD5C28CEE1B25F1CEB64F680" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeSevenMember_F2A88815DD5C28CEE1B25F1CEB64F680" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeEightMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeEightMember_A38B2EA54C46F54E4D835F1CEB642284" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeEightMember_A38B2EA54C46F54E4D835F1CEB642284" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeNineMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeNineMember_34648879C9B678E126C45F1CEB649C32" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeNineMember_34648879C9B678E126C45F1CEB649C32" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeTenMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeTenMember_29CA47CBF745FF4121595F1CEB64D1F4" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeTenMember_29CA47CBF745FF4121595F1CEB64D1F4" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_StockOptionsExercisePriceRangeElevenMember" xlink:label="loc_otex_StockOptionsExercisePriceRangeElevenMember_897DFAB1AE57BDFF1AFE5F1CEB6536A5" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_FEE712E7F23F7A3CC47F5F1CEB62894F" xlink:to="loc_otex_StockOptionsExercisePriceRangeElevenMember_897DFAB1AE57BDFF1AFE5F1CEB6536A5" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SharebasedCompensationSharesAuthorizedunderStockOptionPlansExercisePriceRangeAbstract" xlink:label="loc_otex_SharebasedCompensationSharesAuthorizedunderStockOptionPlansExercisePriceRangeAbstract_DBD2BFAF031B269E2B1D5F1CEB6591E4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7763284785D686BFC6015F1CEB653098" xlink:to="loc_otex_SharebasedCompensationSharesAuthorizedunderStockOptionPlansExercisePriceRangeAbstract_DBD2BFAF031B269E2B1D5F1CEB6591E4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_7E2FDDCD023A0DD7DD9D5F1CEB654E1C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_SharebasedCompensationSharesAuthorizedunderStockOptionPlansExercisePriceRangeAbstract_DBD2BFAF031B269E2B1D5F1CEB6591E4" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_7E2FDDCD023A0DD7DD9D5F1CEB654E1C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_76F63FC052A6A5020C865F1CEB66DACD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_SharebasedCompensationSharesAuthorizedunderStockOptionPlansExercisePriceRangeAbstract_DBD2BFAF031B269E2B1D5F1CEB6591E4" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_76F63FC052A6A5020C865F1CEB66DACD" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsOutstandingAbstract" xlink:label="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsOutstandingAbstract_51A1C1E3620361469BA05F1CEB66AE88" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7763284785D686BFC6015F1CEB653098" xlink:to="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsOutstandingAbstract_51A1C1E3620361469BA05F1CEB66AE88" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_8246204341CCCF5D3AA75F1CEB669825" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsOutstandingAbstract_51A1C1E3620361469BA05F1CEB66AE88" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_8246204341CCCF5D3AA75F1CEB669825" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_F39854E8968D187118A45F1CEB66E0A3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsOutstandingAbstract_51A1C1E3620361469BA05F1CEB66AE88" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_F39854E8968D187118A45F1CEB66E0A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_69E2A29C4B02670D799E5F1CEB679C1B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsOutstandingAbstract_51A1C1E3620361469BA05F1CEB66AE88" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_69E2A29C4B02670D799E5F1CEB679C1B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsExercisableAbstract" xlink:label="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsExercisableAbstract_099960D3F4DB8387E0915F1CEB67143E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_7763284785D686BFC6015F1CEB653098" xlink:to="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsExercisableAbstract_099960D3F4DB8387E0915F1CEB67143E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_47C789D074CC3F1EE2575F1CEB677EFC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsExercisableAbstract_099960D3F4DB8387E0915F1CEB67143E" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_47C789D074CC3F1EE2575F1CEB677EFC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_8A73B2A80ABAAF19ACEC5F1CEB68ECDE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsExercisableAbstract_099960D3F4DB8387E0915F1CEB67143E" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_8A73B2A80ABAAF19ACEC5F1CEB68ECDE" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsSummaryOfOutstandingStockOptionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_EF7CAFFC4E0CBD406A435F1CEE376492" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_EF7CAFFC4E0CBD406A435F1CEE376492" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_8D2F2E21FB4E1CF0775B5F1CEE384AD0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_EF7CAFFC4E0CBD406A435F1CEE376492" xlink:to="loc_us-gaap_AwardTypeAxis_8D2F2E21FB4E1CF0775B5F1CEE384AD0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_25840403C41B6E0D6EF55F1CEE38EBCE_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_8D2F2E21FB4E1CF0775B5F1CEE384AD0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_25840403C41B6E0D6EF55F1CEE38EBCE_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_25840403C41B6E0D6EF55F1CEE38EBCE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_8D2F2E21FB4E1CF0775B5F1CEE384AD0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_25840403C41B6E0D6EF55F1CEE38EBCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_1AD2278A21061CDB162E5F1CEE383550" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_25840403C41B6E0D6EF55F1CEE38EBCE" xlink:to="loc_us-gaap_EmployeeStockOptionMember_1AD2278A21061CDB162E5F1CEE383550" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_9AFF3020E254D4261A475F1CEE3965CD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_EF7CAFFC4E0CBD406A435F1CEE376492" xlink:to="loc_srt_RangeAxis_9AFF3020E254D4261A475F1CEE3965CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_A8A64FC922EC198F6BEB5F1CEE399241_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_9AFF3020E254D4261A475F1CEE3965CD" xlink:to="loc_srt_RangeMember_A8A64FC922EC198F6BEB5F1CEE399241_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_A8A64FC922EC198F6BEB5F1CEE399241" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_9AFF3020E254D4261A475F1CEE3965CD" xlink:to="loc_srt_RangeMember_A8A64FC922EC198F6BEB5F1CEE399241" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_2B7C1E1545F9F9290AE55F1CEE39188E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_A8A64FC922EC198F6BEB5F1CEE399241" xlink:to="loc_srt_MinimumMember_2B7C1E1545F9F9290AE55F1CEE39188E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_AF6D4E59F69911CC42A25F1CEE3A660A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_A8A64FC922EC198F6BEB5F1CEE399241" xlink:to="loc_srt_MaximumMember_AF6D4E59F69911CC42A25F1CEE3A660A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_B062460EE45A2E2BBD6A5F1CEE3AFCCC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_B062460EE45A2E2BBD6A5F1CEE3AFCCC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_1CDCF7E1BFFB75DA7A095F1CEE3A3695" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_1CDCF7E1BFFB75DA7A095F1CEE3A3695" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_9C449D32652323CA86D25F1CEE3B36F3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_9C449D32652323CA86D25F1CEE3B36F3" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirePeriodMinimum" xlink:label="loc_otex_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirePeriodMinimum_367C52F2D0CE12E0D6265F1CEE3BE9D3" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_otex_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirePeriodMinimum_367C52F2D0CE12E0D6265F1CEE3BE9D3" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirePeriodMaximum" xlink:label="loc_otex_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirePeriodMaximum_D34B5425F6C4E6E21BB15F1CEE3BFE95" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_otex_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirePeriodMaximum_D34B5425F6C4E6E21BB15F1CEE3BFE95" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_870997BE653EE40675105F1CEE3BEA73" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_870997BE653EE40675105F1CEE3BEA73" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_F23BDAAB89097063FF875F1CEE3B01D4" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_F23BDAAB89097063FF875F1CEE3B01D4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationCashFlowEffectCashUsedToSettleAwards" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationCashFlowEffectCashUsedToSettleAwards_BF0D6BBCADA7AC01B04D5F1CEE3BB456" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationCashFlowEffectCashUsedToSettleAwards_BF0D6BBCADA7AC01B04D5F1CEE3BB456" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount_C6FFA3400907E5FC801F5F1CEE3C2C6F" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount_C6FFA3400907E5FC801F5F1CEE3C2C6F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_5B5E7A7045AADAFD7C965F1CEE3C709A" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_5B5E7A7045AADAFD7C965F1CEE3C709A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions_884C510F4352669668985F1CEE3C109E" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4D2F16BDDD66E162C2955F1CEE3A9DD3" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions_884C510F4352669668985F1CEE3C109E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsSummaryOfStockOptionsOutstandingUnderVariousStockOptionPlansDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_76AFE888E342D775DFA85F1CF2C9A7D4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_76AFE888E342D775DFA85F1CF2C9A7D4" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_91C1B1206D81C9BBF1D65F1CF2C98E34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_76AFE888E342D775DFA85F1CF2C9A7D4" xlink:to="loc_us-gaap_PlanNameAxis_91C1B1206D81C9BBF1D65F1CF2C98E34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_C14F7041DB4B24A33CE95F1CF2C94094_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_91C1B1206D81C9BBF1D65F1CF2C98E34" xlink:to="loc_us-gaap_PlanNameDomain_C14F7041DB4B24A33CE95F1CF2C94094_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_C14F7041DB4B24A33CE95F1CF2C94094" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_91C1B1206D81C9BBF1D65F1CF2C98E34" xlink:to="loc_us-gaap_PlanNameDomain_C14F7041DB4B24A33CE95F1CF2C94094" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_A2004StockOptionPlanMember" xlink:label="loc_otex_A2004StockOptionPlanMember_E2B557576F07D9DB8BC35F1CF2CA8DB4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_C14F7041DB4B24A33CE95F1CF2C94094" xlink:to="loc_otex_A2004StockOptionPlanMember_E2B557576F07D9DB8BC35F1CF2CA8DB4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_51E524D26A7845E4944C5F1CF2CA73E4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_76AFE888E342D775DFA85F1CF2C9A7D4" xlink:to="loc_srt_RangeAxis_51E524D26A7845E4944C5F1CF2CA73E4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_33F8681E407F2B6DCD385F1CF2CA5855_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_51E524D26A7845E4944C5F1CF2CA73E4" xlink:to="loc_srt_RangeMember_33F8681E407F2B6DCD385F1CF2CA5855_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_33F8681E407F2B6DCD385F1CF2CA5855" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_51E524D26A7845E4944C5F1CF2CA73E4" xlink:to="loc_srt_RangeMember_33F8681E407F2B6DCD385F1CF2CA5855" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_56A3C0ECD98E0EA374A15F1CF2CB75C0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_33F8681E407F2B6DCD385F1CF2CA5855" xlink:to="loc_srt_MinimumMember_56A3C0ECD98E0EA374A15F1CF2CB75C0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_E3D462E037C4CBBF69435F1CF2CBFE34" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_33F8681E407F2B6DCD385F1CF2CA5855" xlink:to="loc_srt_MaximumMember_E3D462E037C4CBBF69435F1CF2CBFE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_697839F8D16676B3921A5F1CF2CB578C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_697839F8D16676B3921A5F1CF2CB578C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_BA948A668D4250A796855F1CF2CCAFFE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_BA948A668D4250A796855F1CF2CCAFFE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_54AAC96847475A167C375F1CF2CC99A1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_54AAC96847475A167C375F1CF2CC99A1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_54556B78C2E447F1914F5F1CF2CC8835" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_54556B78C2E447F1914F5F1CF2CC8835" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsTerminationGracePeriods" xlink:label="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsTerminationGracePeriods_02BCC5901AB8D00CF8255F1CF2CCE359" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:to="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsTerminationGracePeriods_02BCC5901AB8D00CF8255F1CF2CCE359" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsVestingSchedule" xlink:label="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsVestingSchedule_3C06EDDC348838D9959B5F1CF2CC98C9" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:to="loc_otex_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsVestingSchedule_3C06EDDC348838D9959B5F1CF2CC98C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_C878D8CC6E17F7861E405F1CF2CC70C1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_C878D8CC6E17F7861E405F1CF2CC70C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_4A975A395521A61A292D5F1CF2CC3B40" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_4481331E729A7B4C84AA5F1CF2CBA1F1" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_4A975A395521A61A292D5F1CF2CC3B40" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/ShareCapitalOptionPlansAndShareBasedPaymentsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/SpecialChargesRecoveries" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/SpecialChargesRecoveriesAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_271B7CAA8D6CAF5D3CBB8220BB1D3987" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_83F5263560DA1BEF411F8220BB190A96" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_271B7CAA8D6CAF5D3CBB8220BB1D3987" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_83F5263560DA1BEF411F8220BB190A96" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis" xlink:label="loc_srt_RangeAxis_C29C4BAA84BC494895DE8220BB197F75" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_83F5263560DA1BEF411F8220BB190A96" xlink:to="loc_srt_RangeAxis_C29C4BAA84BC494895DE8220BB197F75" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_21D846E2EDFE3F18A06A8220BB1985DD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_C29C4BAA84BC494895DE8220BB197F75" xlink:to="loc_srt_RangeMember_21D846E2EDFE3F18A06A8220BB1985DD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember" xlink:label="loc_srt_RangeMember_21D846E2EDFE3F18A06A8220BB1985DD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_C29C4BAA84BC494895DE8220BB197F75" xlink:to="loc_srt_RangeMember_21D846E2EDFE3F18A06A8220BB1985DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember" xlink:label="loc_srt_MinimumMember_5A277DA1B5277B295A698220BB1924D8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_21D846E2EDFE3F18A06A8220BB1985DD" xlink:to="loc_srt_MinimumMember_5A277DA1B5277B295A698220BB1924D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember" xlink:label="loc_srt_MaximumMember_8AF3AC7E8AF83AB3A7DE8220BB1A30BB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_21D846E2EDFE3F18A06A8220BB1985DD" xlink:to="loc_srt_MaximumMember_8AF3AC7E8AF83AB3A7DE8220BB1A30BB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanAxis" xlink:label="loc_us-gaap_RestructuringPlanAxis_AD45F94486B165D016858220BB1A3C48" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_83F5263560DA1BEF411F8220BB190A96" xlink:to="loc_us-gaap_RestructuringPlanAxis_AD45F94486B165D016858220BB1A3C48" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="loc_us-gaap_RestructuringPlanDomain_1FAB056B34B179CD77338220BB1A3601_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_AD45F94486B165D016858220BB1A3C48" xlink:to="loc_us-gaap_RestructuringPlanDomain_1FAB056B34B179CD77338220BB1A3601_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="loc_us-gaap_RestructuringPlanDomain_1FAB056B34B179CD77338220BB1A3601" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_AD45F94486B165D016858220BB1A3C48" xlink:to="loc_us-gaap_RestructuringPlanDomain_1FAB056B34B179CD77338220BB1A3601" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_COVID19RestructuringPlanMember" xlink:label="loc_otex_COVID19RestructuringPlanMember_88D91333913D74B86FFF8220BB1BC410" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_1FAB056B34B179CD77338220BB1A3601" xlink:to="loc_otex_COVID19RestructuringPlanMember_88D91333913D74B86FFF8220BB1BC410" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2020RestructuringPlanMember" xlink:label="loc_otex_Fiscal2020RestructuringPlanMember_FAB48BA0D9257D0444308220BB1BF001" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_1FAB056B34B179CD77338220BB1A3601" xlink:to="loc_otex_Fiscal2020RestructuringPlanMember_FAB48BA0D9257D0444308220BB1BF001" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2019RestructuringPlanMember" xlink:label="loc_otex_Fiscal2019RestructuringPlanMember_A24D308FFA51558C78E48220BB1B22F4" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_1FAB056B34B179CD77338220BB1A3601" xlink:to="loc_otex_Fiscal2019RestructuringPlanMember_A24D308FFA51558C78E48220BB1B22F4" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2018RestructuringPlanMember" xlink:label="loc_otex_Fiscal2018RestructuringPlanMember_0C1BC396E70C3F87E0C38220BB1BB5F1" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_1FAB056B34B179CD77338220BB1A3601" xlink:to="loc_otex_Fiscal2018RestructuringPlanMember_0C1BC396E70C3F87E0C38220BB1BB5F1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_4BE815C8AE9B3E7727348220BB1BF0CD" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_83F5263560DA1BEF411F8220BB190A96" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_4BE815C8AE9B3E7727348220BB1BF0CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_4BE815C8AE9B3E7727348220BB1BF0CD" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_4BE815C8AE9B3E7727348220BB1BF0CD" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_ROUAssetsAbandonmentMember" xlink:label="loc_otex_ROUAssetsAbandonmentMember_0C1FF4ACD007489EA0AA8220BB1CEA5F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677" xlink:to="loc_otex_ROUAssetsAbandonmentMember_0C1FF4ACD007489EA0AA8220BB1CEA5F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FacilityClosingMember" xlink:label="loc_us-gaap_FacilityClosingMember_B6006ECE3352D72616928220BB1C486B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677" xlink:to="loc_us-gaap_FacilityClosingMember_B6006ECE3352D72616928220BB1C486B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_MiscellaneousOtherChargesMember" xlink:label="loc_otex_MiscellaneousOtherChargesMember_48119C4DDF68288B1F278220BB1CB86C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677" xlink:to="loc_otex_MiscellaneousOtherChargesMember_48119C4DDF68288B1F278220BB1CB86C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_SystemImplementationCostsMember" xlink:label="loc_otex_SystemImplementationCostsMember_D2F5D155891B3D1B37178220BB1DD14D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677" xlink:to="loc_otex_SystemImplementationCostsMember_D2F5D155891B3D1B37178220BB1DD14D" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_PreAcquisitionTaxLiabilitiesBecomingStatuteBarredMember" xlink:label="loc_otex_PreAcquisitionTaxLiabilitiesBecomingStatuteBarredMember_40DD3C52397840D9BA448220BB1DDEA9" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677" xlink:to="loc_otex_PreAcquisitionTaxLiabilitiesBecomingStatuteBarredMember_40DD3C52397840D9BA448220BB1DDEA9" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_PreAcquisitionSalesAndUseTaxLiabilitiesMember" xlink:label="loc_otex_PreAcquisitionSalesAndUseTaxLiabilitiesMember_F4265E4E4F408EA637908220BB1D274D" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_D84A935283FAE6B8727B8220BB1CA677" xlink:to="loc_otex_PreAcquisitionSalesAndUseTaxLiabilitiesMember_F4265E4E4F408EA637908220BB1D274D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringAndRelatedCostExpectedCost1" xlink:label="loc_us-gaap_RestructuringAndRelatedCostExpectedCost1_4318E46FDA886635EF338220BB1DFA0F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_271B7CAA8D6CAF5D3CBB8220BB1D3987" xlink:to="loc_us-gaap_RestructuringAndRelatedCostExpectedCost1_4318E46FDA886635EF338220BB1DFA0F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringAndRelatedCostCostIncurredToDate1" xlink:label="loc_us-gaap_RestructuringAndRelatedCostCostIncurredToDate1_F7BA346C28E186D0EC898220BB1EC7C7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_271B7CAA8D6CAF5D3CBB8220BB1D3987" xlink:to="loc_us-gaap_RestructuringAndRelatedCostCostIncurredToDate1_F7BA346C28E186D0EC898220BB1EC7C7" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_RestructuringChargesRecoveriesOther" xlink:label="loc_otex_RestructuringChargesRecoveriesOther_732A7284837318CEB7268220BB1ED745" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_271B7CAA8D6CAF5D3CBB8220BB1D3987" xlink:to="loc_otex_RestructuringChargesRecoveriesOther_732A7284837318CEB7268220BB1ED745" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1F467828156F5AD3C25A8220BB1E32FF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_271B7CAA8D6CAF5D3CBB8220BB1D3987" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1F467828156F5AD3C25A8220BB1E32FF" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/SpecialChargesRecoveriesScheduleOfRestructuringReserveDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_76DD5D4A6DDBBB3A4F0E8220BB0E7C7E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_535B111DE483B11742D28220BB0B9C4C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_76DD5D4A6DDBBB3A4F0E8220BB0E7C7E" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_535B111DE483B11742D28220BB0B9C4C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_7F58A5004008B9AB4C318220BB0B3471" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_535B111DE483B11742D28220BB0B9C4C" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_7F58A5004008B9AB4C318220BB0B3471" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_D77523C5429B5C754B5D8220BB0B35E2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_7F58A5004008B9AB4C318220BB0B3471" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_D77523C5429B5C754B5D8220BB0B35E2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_D77523C5429B5C754B5D8220BB0B35E2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_7F58A5004008B9AB4C318220BB0B3471" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_D77523C5429B5C754B5D8220BB0B35E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_275D7E8DF46B4251F9C58220BB0CE331" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_D77523C5429B5C754B5D8220BB0B35E2" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_275D7E8DF46B4251F9C58220BB0CE331" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanAxis" xlink:label="loc_us-gaap_RestructuringPlanAxis_DEB68A03AED6FAEB954E8220BB0C528D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_535B111DE483B11742D28220BB0B9C4C" xlink:to="loc_us-gaap_RestructuringPlanAxis_DEB68A03AED6FAEB954E8220BB0C528D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="loc_us-gaap_RestructuringPlanDomain_0B2F842526665C1392268220BB0C216C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_DEB68A03AED6FAEB954E8220BB0C528D" xlink:to="loc_us-gaap_RestructuringPlanDomain_0B2F842526665C1392268220BB0C216C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="loc_us-gaap_RestructuringPlanDomain_0B2F842526665C1392268220BB0C216C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_DEB68A03AED6FAEB954E8220BB0C528D" xlink:to="loc_us-gaap_RestructuringPlanDomain_0B2F842526665C1392268220BB0C216C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_COVID19RestructuringPlanMember" xlink:label="loc_otex_COVID19RestructuringPlanMember_76A69D786629A14FCEBB8220BB0CD55A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_0B2F842526665C1392268220BB0C216C" xlink:to="loc_otex_COVID19RestructuringPlanMember_76A69D786629A14FCEBB8220BB0CD55A" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2020RestructuringPlanMember" xlink:label="loc_otex_Fiscal2020RestructuringPlanMember_2AA6B341637497D224C38220BB0D70AC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_0B2F842526665C1392268220BB0C216C" xlink:to="loc_otex_Fiscal2020RestructuringPlanMember_2AA6B341637497D224C38220BB0D70AC" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2019RestructuringPlanMember" xlink:label="loc_otex_Fiscal2019RestructuringPlanMember_B522B0C3B19419C955598220BB0D51D6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_0B2F842526665C1392268220BB0C216C" xlink:to="loc_otex_Fiscal2019RestructuringPlanMember_B522B0C3B19419C955598220BB0D51D6" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2018RestructuringPlanMember" xlink:label="loc_otex_Fiscal2018RestructuringPlanMember_900CB419D751D5AC7AF18220BB0DA52B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_0B2F842526665C1392268220BB0C216C" xlink:to="loc_otex_Fiscal2018RestructuringPlanMember_900CB419D751D5AC7AF18220BB0DA52B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_E1E5C37E05D3F0FDCC8F8220BB0D7855" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_535B111DE483B11742D28220BB0B9C4C" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_E1E5C37E05D3F0FDCC8F8220BB0D7855" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_34BB67FDC6F1A23A99C38220BB0EB1F7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_E1E5C37E05D3F0FDCC8F8220BB0D7855" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_34BB67FDC6F1A23A99C38220BB0EB1F7_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_34BB67FDC6F1A23A99C38220BB0EB1F7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_E1E5C37E05D3F0FDCC8F8220BB0D7855" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_34BB67FDC6F1A23A99C38220BB0EB1F7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeSeveranceMember" xlink:label="loc_us-gaap_EmployeeSeveranceMember_240703016B2AC75F7A878220BB0E3AA0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_34BB67FDC6F1A23A99C38220BB0EB1F7" xlink:to="loc_us-gaap_EmployeeSeveranceMember_240703016B2AC75F7A878220BB0E3AA0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FacilityClosingMember" xlink:label="loc_us-gaap_FacilityClosingMember_C44657E6F6DCDA399FAB8220BB0E8230" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_34BB67FDC6F1A23A99C38220BB0EB1F7" xlink:to="loc_us-gaap_FacilityClosingMember_C44657E6F6DCDA399FAB8220BB0E8230" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountingStandardsUpdateExtensibleList" xlink:label="loc_us-gaap_AccountingStandardsUpdateExtensibleList_A78F1685E8AB13455F8B8220BB0F4363" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_76DD5D4A6DDBBB3A4F0E8220BB0E7C7E" xlink:to="loc_us-gaap_AccountingStandardsUpdateExtensibleList_A78F1685E8AB13455F8B8220BB0F4363" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringReserveRollForward" xlink:label="loc_us-gaap_RestructuringReserveRollForward_605D3488C129810804E08220BB0FEAA2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_76DD5D4A6DDBBB3A4F0E8220BB0E7C7E" xlink:to="loc_us-gaap_RestructuringReserveRollForward_605D3488C129810804E08220BB0FEAA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringReserve" xlink:label="loc_us-gaap_RestructuringReserve_5DA7028B7CE66135E21D8220BB0FF5A5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_605D3488C129810804E08220BB0FEAA2" xlink:to="loc_us-gaap_RestructuringReserve_5DA7028B7CE66135E21D8220BB0FF5A5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringReserveAccrualAdjustment1" xlink:label="loc_us-gaap_RestructuringReserveAccrualAdjustment1_13FBF7F49D2A8EE202B98220BB108F7E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_605D3488C129810804E08220BB0FEAA2" xlink:to="loc_us-gaap_RestructuringReserveAccrualAdjustment1_13FBF7F49D2A8EE202B98220BB108F7E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRestructuring" xlink:label="loc_us-gaap_PaymentsForRestructuring_6CF3F667B45A62A18CB28220BB1059AE" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_605D3488C129810804E08220BB0FEAA2" xlink:to="loc_us-gaap_PaymentsForRestructuring_6CF3F667B45A62A18CB28220BB1059AE" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_RestructuringReserveForeignCurrencyTranslationGainLossandSettledwithoutCash" xlink:label="loc_otex_RestructuringReserveForeignCurrencyTranslationGainLossandSettledwithoutCash_6FC983B473CB6C6BFC958220BB10096F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_605D3488C129810804E08220BB0FEAA2" xlink:to="loc_otex_RestructuringReserveForeignCurrencyTranslationGainLossandSettledwithoutCash_6FC983B473CB6C6BFC958220BB10096F" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/SpecialChargesRecoveriesScheduleOfSpecialChargesRelatedToRestructuringPlanDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_CD1A81DF959264A3F19E5F1CF2B170BD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_B80F29882F8EF2C2E8245F1CF2AE0C99" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CD1A81DF959264A3F19E5F1CF2B170BD" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_B80F29882F8EF2C2E8245F1CF2AE0C99" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanAxis" xlink:label="loc_us-gaap_RestructuringPlanAxis_8A8AB5FFFDA24A5F006C5F1CF2AE50E4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_B80F29882F8EF2C2E8245F1CF2AE0C99" xlink:to="loc_us-gaap_RestructuringPlanAxis_8A8AB5FFFDA24A5F006C5F1CF2AE50E4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="loc_us-gaap_RestructuringPlanDomain_AF6C729387966E75C57D5F1CF2AFE16F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_8A8AB5FFFDA24A5F006C5F1CF2AE50E4" xlink:to="loc_us-gaap_RestructuringPlanDomain_AF6C729387966E75C57D5F1CF2AFE16F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="loc_us-gaap_RestructuringPlanDomain_AF6C729387966E75C57D5F1CF2AFE16F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_8A8AB5FFFDA24A5F006C5F1CF2AE50E4" xlink:to="loc_us-gaap_RestructuringPlanDomain_AF6C729387966E75C57D5F1CF2AFE16F" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_COVID19RestructuringPlanMember" xlink:label="loc_otex_COVID19RestructuringPlanMember_198C7D449382BE887C905F1CF2AFD251" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_AF6C729387966E75C57D5F1CF2AFE16F" xlink:to="loc_otex_COVID19RestructuringPlanMember_198C7D449382BE887C905F1CF2AFD251" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2020RestructuringPlanMember" xlink:label="loc_otex_Fiscal2020RestructuringPlanMember_65F3AF84CB919E6B543D5F1CF2B089F4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_AF6C729387966E75C57D5F1CF2AFE16F" xlink:to="loc_otex_Fiscal2020RestructuringPlanMember_65F3AF84CB919E6B543D5F1CF2B089F4" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2019RestructuringPlanMember" xlink:label="loc_otex_Fiscal2019RestructuringPlanMember_A6AC9735C86D9F1FDD975F1CF2B0480B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_AF6C729387966E75C57D5F1CF2AFE16F" xlink:to="loc_otex_Fiscal2019RestructuringPlanMember_A6AC9735C86D9F1FDD975F1CF2B0480B" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2018RestructuringPlanMember" xlink:label="loc_otex_Fiscal2018RestructuringPlanMember_360D1E973F3CD775A4F55F1CF2B0C70D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_AF6C729387966E75C57D5F1CF2AFE16F" xlink:to="loc_otex_Fiscal2018RestructuringPlanMember_360D1E973F3CD775A4F55F1CF2B0C70D" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_RestructuringPlansPriorPeriodsMember" xlink:label="loc_otex_RestructuringPlansPriorPeriodsMember_68226B92CB3C7C7721875F1CF2B02FAF" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_AF6C729387966E75C57D5F1CF2AFE16F" xlink:to="loc_otex_RestructuringPlansPriorPeriodsMember_68226B92CB3C7C7721875F1CF2B02FAF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_46FA3B21CEBE758E81E65F1CF2B11F15" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CD1A81DF959264A3F19E5F1CF2B170BD" xlink:to="loc_us-gaap_RestructuringCharges_46FA3B21CEBE758E81E65F1CF2B11F15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_5E996B8FD0F4D6C38A775F1CF2B1A889" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CD1A81DF959264A3F19E5F1CF2B170BD" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_5E996B8FD0F4D6C38A775F1CF2B1A889" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_RestructuringChargesRecoveriesOther" xlink:label="loc_otex_RestructuringChargesRecoveriesOther_2A681D1971BC1BA9EDCB5F1CF2B20E1A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CD1A81DF959264A3F19E5F1CF2B170BD" xlink:to="loc_otex_RestructuringChargesRecoveriesOther_2A681D1971BC1BA9EDCB5F1CF2B20E1A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringSettlementAndImpairmentProvisions" xlink:label="loc_us-gaap_RestructuringSettlementAndImpairmentProvisions_41E8B745400417CB602B5F1CF2B238FF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CD1A81DF959264A3F19E5F1CF2B170BD" xlink:to="loc_us-gaap_RestructuringSettlementAndImpairmentProvisions_41E8B745400417CB602B5F1CF2B238FF" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/SpecialChargesRecoveriesTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_22101E75F4B0F9868B9C5F1CF2A6F56E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_D48F81C1FD6B75B3BC985F1CF2A4602E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_22101E75F4B0F9868B9C5F1CF2A6F56E" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_D48F81C1FD6B75B3BC985F1CF2A4602E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanAxis" xlink:label="loc_us-gaap_RestructuringPlanAxis_82ED1DC036D4DB92CD2C5F1CF2A4953C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_D48F81C1FD6B75B3BC985F1CF2A4602E" xlink:to="loc_us-gaap_RestructuringPlanAxis_82ED1DC036D4DB92CD2C5F1CF2A4953C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="loc_us-gaap_RestructuringPlanDomain_DD2FCE0FA5A140D0F9075F1CF2A5D346_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_82ED1DC036D4DB92CD2C5F1CF2A4953C" xlink:to="loc_us-gaap_RestructuringPlanDomain_DD2FCE0FA5A140D0F9075F1CF2A5D346_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="loc_us-gaap_RestructuringPlanDomain_DD2FCE0FA5A140D0F9075F1CF2A5D346" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_82ED1DC036D4DB92CD2C5F1CF2A4953C" xlink:to="loc_us-gaap_RestructuringPlanDomain_DD2FCE0FA5A140D0F9075F1CF2A5D346" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_COVID19RestructuringPlanMember" xlink:label="loc_otex_COVID19RestructuringPlanMember_04AA0D59AAFE77C8AAB75F1CF2A5BF20" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_DD2FCE0FA5A140D0F9075F1CF2A5D346" xlink:to="loc_otex_COVID19RestructuringPlanMember_04AA0D59AAFE77C8AAB75F1CF2A5BF20" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2020RestructuringPlanMember" xlink:label="loc_otex_Fiscal2020RestructuringPlanMember_14C30615F9CF82D556965F1CF2A5BC2C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_DD2FCE0FA5A140D0F9075F1CF2A5D346" xlink:to="loc_otex_Fiscal2020RestructuringPlanMember_14C30615F9CF82D556965F1CF2A5BC2C" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2019RestructuringPlanMember" xlink:label="loc_otex_Fiscal2019RestructuringPlanMember_71AEFC952F7786C83F5B5F1CF2A6E137" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_DD2FCE0FA5A140D0F9075F1CF2A5D346" xlink:to="loc_otex_Fiscal2019RestructuringPlanMember_71AEFC952F7786C83F5B5F1CF2A6E137" xlink:type="arc" />
    <link:loc xlink:href="otex-20200630.xsd#otex_Fiscal2018RestructuringPlanMember" xlink:label="loc_otex_Fiscal2018RestructuringPlanMember_C1703FEB7871592846E15F1CF2A6D71E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_DD2FCE0FA5A140D0F9075F1CF2A5D346" xlink:to="loc_otex_Fiscal2018RestructuringPlanMember_C1703FEB7871592846E15F1CF2A6D71E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock_43E045893F507CE596445F1CF2A69245" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_22101E75F4B0F9868B9C5F1CF2A6F56E" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock_43E045893F507CE596445F1CF2A69245" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/SubsequentEvents" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/SubsequentEventsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="loc_us-gaap_SubsequentEventLineItems_217049916A446226A1EB5F1CF052717C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="loc_us-gaap_SubsequentEventTable_5338BEAFE574A000CC975F1CF0501C7B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_217049916A446226A1EB5F1CF052717C" xlink:to="loc_us-gaap_SubsequentEventTable_5338BEAFE574A000CC975F1CF0501C7B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_A7AE3898A607FFAC4C505F1CF0507021" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_5338BEAFE574A000CC975F1CF0501C7B" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_A7AE3898A607FFAC4C505F1CF0507021" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_95CE1C55DA6C244147195F1CF051AF89_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_A7AE3898A607FFAC4C505F1CF0507021" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_95CE1C55DA6C244147195F1CF051AF89_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_95CE1C55DA6C244147195F1CF051AF89" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_A7AE3898A607FFAC4C505F1CF0507021" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_95CE1C55DA6C244147195F1CF051AF89" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_40CA05D02250D85CE1E65F1CF051BFFA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_95CE1C55DA6C244147195F1CF051AF89" xlink:to="loc_us-gaap_SubsequentEventMember_40CA05D02250D85CE1E65F1CF051BFFA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_00900FA06583EF33569C5F1CF0527550" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_217049916A446226A1EB5F1CF052717C" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_00900FA06583EF33569C5F1CF0527550" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://opentext.com/role/SupplementalCashFlowDisclosures" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/SupplementalCashFlowDisclosuresDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://opentext.com/role/SupplementalCashFlowDisclosuresTables" xlink:type="extended" />
</link:linkbase>
