<?xml version="1.0" encoding="us-ascii"?>
<!-- DFS ActiveDisclosure(SM) XBRL Schema Document - http://www.dfsco.com/financial-services/ -->
<!-- Creation Date      : 2018-07-31T22:34:50.6305879+00:00 -->
<!-- Version            : 2.12.6766.32775 -->
<!-- Package ID         : 1514fb2597584061abf5cc7c3c51528e -->
<!-- Copyright (c) 2018 Donnelley Financial, LLC. All Rights Reserved. -->
<schema xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:num="http://www.xbrl.org/dtr/type/numeric" xmlns:us-types="http://fasb.org/us-types/2018-01-31" xmlns:stpr="http://xbrl.sec.gov/stpr/2018-01-31" xmlns:srt-types="http://fasb.org/srt-types/2018-01-31" xmlns:naics="http://xbrl.sec.gov/naics/2017-01-31" xmlns:invest="http://xbrl.sec.gov/invest/2013-01-31" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:srt="http://fasb.org/srt/2018-01-31" xmlns:us-gaap="http://fasb.org/us-gaap/2018-01-31" xmlns:dei="http://xbrl.sec.gov/dei/2018-01-31" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:country="http://xbrl.sec.gov/country/2017-01-31" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:currency="http://xbrl.sec.gov/currency/2017-01-31" xmlns:exch="http://xbrl.sec.gov/exch/2018-01-31" xmlns:sic="http://xbrl.sec.gov/sic/2011-01-31" xmlns:amrn="http://www.amarincorp.com/20180630" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.amarincorp.com/20180630" xmlns="http://www.w3.org/2001/XMLSchema">
  <import schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/instance" />
  <import schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/linkbase" />
  <import schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" namespace="http://xbrl.org/2005/xbrldt" />
  <import schemaLocation="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd" namespace="http://xbrl.sec.gov/dei/2018-01-31" />
  <import schemaLocation="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd" namespace="http://fasb.org/us-gaap/2018-01-31" />
  <import schemaLocation="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd" namespace="http://fasb.org/srt/2018-01-31" />
  <import schemaLocation="http://xbrl.fasb.org/us-gaap/2018/elts/us-types-2018-01-31.xsd" namespace="http://fasb.org/us-types/2018-01-31" />
  <import schemaLocation="http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd" namespace="http://www.xbrl.org/dtr/type/numeric" />
  <import schemaLocation="http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd" namespace="http://www.xbrl.org/dtr/type/non-numeric" />
  <import schemaLocation="http://xbrl.fasb.org/srt/2018/elts/srt-types-2018-01-31.xsd" namespace="http://fasb.org/srt-types/2018-01-31" />
  <import schemaLocation="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd" namespace="http://xbrl.sec.gov/country/2017-01-31" />
  <import schemaLocation="https://xbrl.sec.gov/currency/2017/currency-2017-01-31.xsd" namespace="http://xbrl.sec.gov/currency/2017-01-31" />
  <import schemaLocation="https://xbrl.sec.gov/exch/2018/exch-2018-01-31.xsd" namespace="http://xbrl.sec.gov/exch/2018-01-31" />
  <import schemaLocation="https://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd" namespace="http://xbrl.sec.gov/invest/2013-01-31" />
  <import schemaLocation="https://xbrl.sec.gov/naics/2017/naics-2017-01-31.xsd" namespace="http://xbrl.sec.gov/naics/2017-01-31" />
  <import schemaLocation="https://xbrl.sec.gov/sic/2011/sic-2011-01-31.xsd" namespace="http://xbrl.sec.gov/sic/2011-01-31" />
  <import schemaLocation="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd" namespace="http://xbrl.sec.gov/stpr/2018-01-31" />
  <annotation>
    <appinfo>
      <link:roleType id="TemplateLink" roleURI="http://www.amarincorp.com/20180630/role/TemplateLink" xmlns:link="http://www.xbrl.org/2003/linkbase">
        <link:definition>00000 - Document - Template Link</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="amrn-20180630_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:title="Calculation Links, all" xlink:type="simple" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="amrn-20180630_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:title="Definition Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="amrn-20180630_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:title="Label Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="amrn-20180630_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:title="Presentation Links, all" xlink:type="simple" />
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DocumentDocumentAndEntityInformation" id="Role_DocumentDocumentAndEntityInformation">
        <link:definition>100000 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/StatementCondensedConsolidatedBalanceSheets" id="Role_StatementCondensedConsolidatedBalanceSheets">
        <link:definition>100010 - Statement - Condensed Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/StatementCondensedConsolidatedBalanceSheetsParenthetical" id="Role_StatementCondensedConsolidatedBalanceSheetsParenthetical">
        <link:definition>100020 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/StatementCondensedConsolidatedStatementsOfOperations" id="Role_StatementCondensedConsolidatedStatementsOfOperations">
        <link:definition>100030 - Statement - Condensed Consolidated Statements of Operations</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/StatementCondensedConsolidatedStatementOfChangesInStockholdersDeficit" id="Role_StatementCondensedConsolidatedStatementOfChangesInStockholdersDeficit">
        <link:definition>100040 - Statement - Condensed Consolidated Statement of Changes in Stockholders&apos; Deficit</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/StatementCondensedConsolidatedStatementsOfCashFlows" id="Role_StatementCondensedConsolidatedStatementsOfCashFlows">
        <link:definition>100050 - Statement - Condensed Consolidated Statements of Cash Flows</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureNatureOfBusinessAndBasisOfPresentation" id="Role_DisclosureNatureOfBusinessAndBasisOfPresentation">
        <link:definition>100060 - Disclosure - Nature of Business and Basis of Presentation</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureSignificantAccountingPolicies" id="Role_DisclosureSignificantAccountingPolicies">
        <link:definition>100070 - Disclosure - Significant Accounting Policies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureIntangibleAsset" id="Role_DisclosureIntangibleAsset">
        <link:definition>100080 - Disclosure - Intangible Asset</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureInventory" id="Role_DisclosureInventory">
        <link:definition>100090 - Disclosure - Inventory</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureDebt" id="Role_DisclosureDebt">
        <link:definition>100100 - Disclosure - Debt</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureCommitmentsAndContingencies" id="Role_DisclosureCommitmentsAndContingencies">
        <link:definition>100110 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureEquity" id="Role_DisclosureEquity">
        <link:definition>100120 - Disclosure - Equity</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureCoPromotionAgreement" id="Role_DisclosureCoPromotionAgreement">
        <link:definition>100130 - Disclosure - Co-Promotion Agreement</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureRevenueRecognition" id="Role_DisclosureRevenueRecognition">
        <link:definition>100140 - Disclosure - Revenue Recognition</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureDevelopmentCommercializationAndSupplyAgreements" id="Role_DisclosureDevelopmentCommercializationAndSupplyAgreements">
        <link:definition>100150 - Disclosure - Development, Commercialization and Supply Agreements</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureSubsequentEvents" id="Role_DisclosureSubsequentEvents">
        <link:definition>100160 - Disclosure - Subsequent Events</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureSignificantAccountingPoliciesPolicies" id="Role_DisclosureSignificantAccountingPoliciesPolicies">
        <link:definition>100170 - Disclosure - Significant Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureSignificantAccountingPoliciesTables" id="Role_DisclosureSignificantAccountingPoliciesTables">
        <link:definition>100180 - Disclosure - Significant Accounting Policies (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureIntangibleAssetTables" id="Role_DisclosureIntangibleAssetTables">
        <link:definition>100190 - Disclosure - Intangible Asset (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureInventoryTables" id="Role_DisclosureInventoryTables">
        <link:definition>100200 - Disclosure - Inventory (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureRevenueRecognitionTables" id="Role_DisclosureRevenueRecognitionTables">
        <link:definition>100210 - Disclosure - Revenue Recognition (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureDevelopmentCommercializationAndSupplyAgreementsTables" id="Role_DisclosureDevelopmentCommercializationAndSupplyAgreementsTables">
        <link:definition>100220 - Disclosure - Development, Commercialization and Supply Agreements (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureNatureOfBusinessAndBasisOfPresentationAdditionalInformationDetail" id="Role_DisclosureNatureOfBusinessAndBasisOfPresentationAdditionalInformationDetail">
        <link:definition>100230 - Disclosure - Nature of Business and Basis of Presentation - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureSignificantAccountingPoliciesAdditionalInformationDetail" id="Role_DisclosureSignificantAccountingPoliciesAdditionalInformationDetail">
        <link:definition>100240 - Disclosure - Significant Accounting Policies - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureSummarizesImpactOfAccountsReceivableReservesOnGrossTradeAccountsReceivableDetail" id="Role_DisclosureSummarizesImpactOfAccountsReceivableReservesOnGrossTradeAccountsReceivableDetail">
        <link:definition>100250 - Disclosure - Summarizes the Impact of Accounts Receivable Reserves on Gross Trade Accounts Receivable (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureEstimatedUsefulLivesDetail" id="Role_DisclosureEstimatedUsefulLivesDetail">
        <link:definition>100260 - Disclosure - Estimated Useful Lives (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureNetLossAndNumberOfSharesUsedToComputeBasicAndDilutedLossPerShareDetail" id="Role_DisclosureNetLossAndNumberOfSharesUsedToComputeBasicAndDilutedLossPerShareDetail">
        <link:definition>100270 - Disclosure - Net Loss and the Number of Shares Used to Compute Basic and Diluted Loss per Share (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureAntiDilutiveSecuritiesNotIncludedInComputationOfNetLossPerShareDetail" id="Role_DisclosureAntiDilutiveSecuritiesNotIncludedInComputationOfNetLossPerShareDetail">
        <link:definition>100280 - Disclosure - Anti-Dilutive Securities Not Included in the Computation of Net Loss per Share (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureAssetsAndLiabilityMeasuredAtFairValueOnRecurringBasisDetail" id="Role_DisclosureAssetsAndLiabilityMeasuredAtFairValueOnRecurringBasisDetail">
        <link:definition>100290 - Disclosure - Assets and Liability Measured at Fair Value on Recurring Basis (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureCarryingAmountsAndEstimatedFairValuesOfDebtInstrumentsDetail" id="Role_DisclosureCarryingAmountsAndEstimatedFairValuesOfDebtInstrumentsDetail">
        <link:definition>100300 - Disclosure - Carrying Amounts and Estimated Fair Values of Debt Instruments (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureIntangibleAssetAdditionalInformationDetail" id="Role_DisclosureIntangibleAssetAdditionalInformationDetail">
        <link:definition>100310 - Disclosure - Intangible Asset - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureIntangibleAssetDetail" id="Role_DisclosureIntangibleAssetDetail">
        <link:definition>100320 - Disclosure - Intangible Asset (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureInventoryDetail" id="Role_DisclosureInventoryDetail">
        <link:definition>100330 - Disclosure - Inventory (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureDebtLongTermDebtFromRoyaltyBearingInstrumentDecember2012FinancingAdditionalInformationDetail" id="Role_DisclosureDebtLongTermDebtFromRoyaltyBearingInstrumentDecember2012FinancingAdditionalInformationDetail">
        <link:definition>100340 - Disclosure - Debt - Long-Term Debt from Royalty-Bearing Instrument-December 2012 Financing - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureDebtJanuary2012May2014AndNovember2015ExchangeableSeniorNotesAdditionalInformationDetail" id="Role_DisclosureDebtJanuary2012May2014AndNovember2015ExchangeableSeniorNotesAdditionalInformationDetail">
        <link:definition>100350 - Disclosure - Debt - January 2012, May 2014, and November 2015 Exchangeable Senior Notes - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureDebtJanuary2017ExchangeableSeniorNotesAdditionalInformationDetail" id="Role_DisclosureDebtJanuary2017ExchangeableSeniorNotesAdditionalInformationDetail">
        <link:definition>100360 - Disclosure - Debt - January 2017 Exchangeable Senior Notes - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetail" id="Role_DisclosureCommitmentsAndContingenciesAdditionalInformationDetail">
        <link:definition>100370 - Disclosure - Commitments and Contingencies - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureEquityPreferredStockAdditionalInformationDetail" id="Role_DisclosureEquityPreferredStockAdditionalInformationDetail">
        <link:definition>100380 - Disclosure - Equity - Preferred Stock - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureEquityCommonStockAdditionalInformationDetail" id="Role_DisclosureEquityCommonStockAdditionalInformationDetail">
        <link:definition>100390 - Disclosure - Equity - Common Stock - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureEquityIncentiveEquityAwardsAdditionalInformationDetail" id="Role_DisclosureEquityIncentiveEquityAwardsAdditionalInformationDetail">
        <link:definition>100400 - Disclosure - Equity - Incentive Equity Awards - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureCoPromotionAgreementAdditionalInformationDetail" id="Role_DisclosureCoPromotionAgreementAdditionalInformationDetail">
        <link:definition>100410 - Disclosure - Co-Promotion Agreement - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureRevenueRecognitionAdditionalInformationDetail" id="Role_DisclosureRevenueRecognitionAdditionalInformationDetail">
        <link:definition>100420 - Disclosure - Revenue Recognition - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureSummarizeActivityOfNetProductRevenueAllowanceAndReserveCategoriesDetail" id="Role_DisclosureSummarizeActivityOfNetProductRevenueAllowanceAndReserveCategoriesDetail">
        <link:definition>100430 - Disclosure - Summarize Activity of the Net Product Revenue Allowance and Reserve Categories (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureDevelopmentCommercializationAndSupplyAgreementAdditionalInformationDetail" id="Role_DisclosureDevelopmentCommercializationAndSupplyAgreementAdditionalInformationDetail">
        <link:definition>100440 - Disclosure - Development, Commercialization and Supply Agreement - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureDevelopmentCommercializationAndSupplyAgreementChangesInBalancesOfContractAssetsAndLiabilitiesDetail" id="Role_DisclosureDevelopmentCommercializationAndSupplyAgreementChangesInBalancesOfContractAssetsAndLiabilitiesDetail">
        <link:definition>100450 - Disclosure - Development, Commercialization and Supply Agreement - Changes in Balances of Contract Assets and Liabilities (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.amarincorp.com/20180630/taxonomy/role/DisclosureDevelopmentCommercializationAndSupplyAgreementRecognizedRevenuesChangesInContractAssetAndContractLiabilityBalancesDetail" id="Role_DisclosureDevelopmentCommercializationAndSupplyAgreementRecognizedRevenuesChangesInContractAssetAndContractLiabilityBalancesDetail">
        <link:definition>100460 - Disclosure - Development, Commercialization and Supply Agreement - Recognized Revenues Changes in Contract Asset and Contract Liability Balances (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </appinfo>
  </annotation>
  <element id="amrn_DocumentAndEntityInformationAbstract" name="DocumentAndEntityInformationAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_AmericanDepositaryShareMember" name="AmericanDepositaryShareMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_OrdinarySharesMember" name="OrdinarySharesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_PreferredStockEquivalentOrdinarySharesUponFutureConversionOutstanding" name="PreferredStockEquivalentOrdinarySharesUponFutureConversionOutstanding" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <element id="amrn_SharesOutstandingAdjustedBalance" name="SharesOutstandingAdjustedBalance" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <element id="amrn_StockholdersEquityAdjustedBalance" name="StockholdersEquityAdjustedBalance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_ProceedsFromIssuanceOfExchangeableDebt" name="ProceedsFromIssuanceOfExchangeableDebt" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <element id="amrn_CashPaidDuringPeriodForAbstract" name="CashPaidDuringPeriodForAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_CoPromotionAgreementDisclosureTextBlock" name="CoPromotionAgreementDisclosureTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_CoPromotionAgreementAbstract" name="CoPromotionAgreementAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_UseOfForecastedFinancialInformationInAccountingEstimatesPolicyTextBlock" name="UseOfForecastedFinancialInformationInAccountingEstimatesPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_ConcentrationOfSuppliersPolicyTextBlock" name="ConcentrationOfSuppliersPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_PropertyPlantAndEquipmentUsefulLifeTableTextBlock" name="PropertyPlantAndEquipmentUsefulLifeTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_SummaryOfNetProductRevenueValuationAllowancesTableTextBlock" name="SummaryOfNetProductRevenueValuationAllowancesTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_NumberOfPatientsEnrolledAndRandomizedInStudy" name="NumberOfPatientsEnrolledAndRandomizedInStudy" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItems" name="OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTable" name="OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_SeniorNotesFourMember" name="SeniorNotesFourMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_NumberOfSalesProfessionals" name="NumberOfSalesProfessionals" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_DebtInstrumentMaturityDateYear" name="DebtInstrumentMaturityDateYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_AccountsReceivableCreditPeriod" name="AccountsReceivableCreditPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_SignificantAccountingPoliciesLineItems" name="SignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_SignificantAccountingPoliciesTable" name="SignificantAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_CustomerAMember" name="CustomerAMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_CustomerBMember" name="CustomerBMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_CustomerCMember" name="CustomerCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_BiopharmaceuticalMember" name="BiopharmaceuticalMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_AllowanceForEstimatedChargebacksMember" name="AllowanceForEstimatedChargebacksMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_ComputerEquipmentAndCapitalizedSoftwareMember" name="ComputerEquipmentAndCapitalizedSoftwareMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_NetIncomeLossAvailableToCommonStockholdersBasicAndDiluted" name="NetIncomeLossAvailableToCommonStockholdersBasicAndDiluted" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_LongTermDebtCurrentNetOfAccruedInterest" name="LongTermDebtCurrentNetOfAccruedInterest" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_SeniorNotesSixMember" name="SeniorNotesSixMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_LongTermDebtFairValueCurrentNetOfAccruedInterest" name="LongTermDebtFairValueCurrentNetOfAccruedInterest" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_LongTermDebtFairValueNoncurrent" name="LongTermDebtFairValueNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_DerivativeLiabilityFairValueAssumptionsExpectedTerm" name="DerivativeLiabilityFairValueAssumptionsExpectedTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_FairValueAssumptionsCouponRate" name="FairValueAssumptionsCouponRate" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_FairValueAssumptionsComparableYieldToMaturity" name="FairValueAssumptionsComparableYieldToMaturity" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_DebtDisclosureLineItems" name="DebtDisclosureLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_DebtDisclosureTable" name="DebtDisclosureTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_CPPIBMember" name="CPPIBMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_RoyaltyBearingDebtMember" name="RoyaltyBearingDebtMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_ChargesCashMember" name="ChargesCashMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_NonCashMember" name="NonCashMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_GuaranteePayments" name="GuaranteePayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <element id="amrn_FutureMinimumGuaranteePayments" name="FutureMinimumGuaranteePayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_DebtInstrumentAggregatePrincipalAmountRedeemed" name="DebtInstrumentAggregatePrincipalAmountRedeemed" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <element id="amrn_SeniorNotesOneMember" name="SeniorNotesOneMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_TwoThousandTwelveTwoThousandFourteenAndTwoThousandFifteenNotesMember" name="TwoThousandTwelveTwoThousandFourteenAndTwoThousandFifteenNotesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_DebtInstrumentConvertiblePremiumOnConversionPricePercentage" name="DebtInstrumentConvertiblePremiumOnConversionPricePercentage" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_ExcessPrincipalValueOverFairValue" name="ExcessPrincipalValueOverFairValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_DebtInstrumentDebtDefaultThresholdPercentageOfPrincipalAmountToIssueNotice" name="DebtInstrumentDebtDefaultThresholdPercentageOfPrincipalAmountToIssueNotice" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_CommitmentsAndContingenciesDisclosureLineItems" name="CommitmentsAndContingenciesDisclosureLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_CommitmentsAndContingenciesDisclosureTable" name="CommitmentsAndContingenciesDisclosureTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_TevaPharmaceuticalsUSAIncMember" name="TevaPharmaceuticalsUSAIncMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_NisshinPharmaIncMember" name="NisshinPharmaIncMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_FurtherIndicationForAMROneZeroOneMember" name="FurtherIndicationForAMROneZeroOneMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_BusinessDevelopmentsAxis" name="BusinessDevelopmentsAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_BusinessDevelopmentDomain" name="BusinessDevelopmentDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_MarketingApprovalInEuropeMember" name="MarketingApprovalInEuropeMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_PotentialMarketingApprovalOneMember" name="PotentialMarketingApprovalOneMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_PotentialMarketingApprovalTwoMember" name="PotentialMarketingApprovalTwoMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_RoyaltyMilestoneOrMinimumPurchaseCommitments" name="RoyaltyMilestoneOrMinimumPurchaseCommitments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_PrivatePlacementClosingDate" name="PrivatePlacementClosingDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_StockholdersEquityNoteLineItems" name="StockholdersEquityNoteLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_StockholdersEquityNoteTable" name="StockholdersEquityNoteTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_PreferredSharesBasisMember" name="PreferredSharesBasisMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_OrdinarySharesBasisMember" name="OrdinarySharesBasisMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_SecondPrivatePlacementMember" name="SecondPrivatePlacementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_PreferredStockPurchaseOptionMember" name="PreferredStockPurchaseOptionMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_ConversionPricePerShare" name="ConversionPricePerShare" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <element id="amrn_EquityOfferingCosts" name="EquityOfferingCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_BeneficialOwnershipLimitationPercentage" name="BeneficialOwnershipLimitationPercentage" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_DerivativeLiabilitiesTransferredToStockholdersEquity" name="DerivativeLiabilitiesTransferredToStockholdersEquity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <element id="amrn_PublicOfferingOverAllotmentOptionExercisePeriod" name="PublicOfferingOverAllotmentOptionExercisePeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_StockIssuedDuringPeriodSharesNewIssuesExercised" name="StockIssuedDuringPeriodSharesNewIssuesExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_PercentageOfOutstandingCommonSharesAndPreferredSharesOnFullyDilutedBasis" name="PercentageOfOutstandingCommonSharesAndPreferredSharesOnFullyDilutedBasis" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <element id="amrn_StockIncentivePlanTwentyElevenMember" name="StockIncentivePlanTwentyElevenMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_VestingPeriodMember" name="VestingPeriodMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_VestingPeriodFiveMember" name="VestingPeriodFiveMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSettlement" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSettlement" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_AgreementAmendedDate" name="AgreementAmendedDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_CoPromotionAgreementLineItems" name="CoPromotionAgreementLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_CoPromotionAgreementTable" name="CoPromotionAgreementTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_CoPromotionAgreementMember" name="CoPromotionAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_KowaPharmaceuticalsAmericaMember" name="KowaPharmaceuticalsAmericaMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_PercentageOfGrossMarginPayableForPromotionAgreement" name="PercentageOfGrossMarginPayableForPromotionAgreement" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_RangeOfPercentageOfGrossMarginPayableForCoPromotionAgreement" name="RangeOfPercentageOfGrossMarginPayableForCoPromotionAgreement" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_MaximumCoPromotionTailPaymentsReceivePeriod" name="MaximumCoPromotionTailPaymentsReceivePeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_AccruedCoPromotionTailPayments" name="AccruedCoPromotionTailPayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_VascepaOneGramMember" name="VascepaOneGramMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_VascepaHalfGramMember" name="VascepaHalfGramMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_CashDiscountPercent" name="CashDiscountPercent" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <element id="amrn_ProductExpirationPeriodUponConversionIntoCapsuleForm" name="ProductExpirationPeriodUponConversionIntoCapsuleForm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_ProvisionRelatedToPriorPeriodSales" name="ProvisionRelatedToPriorPeriodSales" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <element id="amrn_CreditsPaymentsMadeForPriorPeriodSales" name="CreditsPaymentsMadeForPriorPeriodSales" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <element id="amrn_RebatesChargebacksAndDiscountsMember" name="RebatesChargebacksAndDiscountsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_ProductReturnsMember" name="ProductReturnsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_OtherIncentiveProgramsMember" name="OtherIncentiveProgramsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_NonRefundableAndNonCreditableUpfrontPayment" name="NonRefundableAndNonCreditableUpfrontPayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_LicenseAndCollaborationAgreementsLineItems" name="LicenseAndCollaborationAgreementsLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_LicenseAndCollaborationAgreementsTable" name="LicenseAndCollaborationAgreementsTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_MochidaPharmaceuticalCoLtdMember" name="MochidaPharmaceuticalCoLtdMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_InLicensesAgreementMember" name="InLicensesAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_EddingpharmMember" name="EddingpharmMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_OutLicensesAgreementMember" name="OutLicensesAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_ClinicalTrialApplicationMember" name="ClinicalTrialApplicationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_BiologixMember" name="BiologixMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_HLSTherapeuticsIncorporationMember" name="HLSTherapeuticsIncorporationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <element id="amrn_NonRefundableUpfrontPaymentsReceived" name="NonRefundableUpfrontPaymentsReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <element id="amrn_NonrefundableMilestonePayment" name="NonrefundableMilestonePayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_EligibleMilestonePayment" name="EligibleMilestonePayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_NumberOfRegulatoryMilestoneEventsIndications" name="NumberOfRegulatoryMilestoneEventsIndications" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_EligibleRegulatoryMilestoneEventPayment" name="EligibleRegulatoryMilestoneEventPayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_EligibleSalesBasedMilestoneEventPayment" name="EligibleSalesBasedMilestoneEventPayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <element id="amrn_DeferredRevenueRecognitionPeriod" name="DeferredRevenueRecognitionPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_NonRefundableUpfrontPaymentsReceivedPeriod" name="NonRefundableUpfrontPaymentsReceivedPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <element id="amrn_ContractWithCustomerAssetsAdditions" name="ContractWithCustomerAssetsAdditions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <element id="amrn_ContractWithCustomerAssetDeductions" name="ContractWithCustomerAssetDeductions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
</schema>
