<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2020-12-14</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001739104</issuerCik>
        <issuerName>Elanco Animal Health Inc</issuerName>
        <issuerTradingSymbol>ELAN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001194459</rptOwnerCik>
            <rptOwnerName>DOYLE WILLIAM F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ELANCO ANIMAL HEALTH INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>2500 INNOVATION WAY</rptOwnerStreet2>
            <rptOwnerCity>GREENFIELD</rptOwnerCity>
            <rptOwnerState>IN</rptOwnerState>
            <rptOwnerZipCode>46140</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <remarks>EXHIBIT LIST - Exhibit 24 - Power of Attorney for William F. Doyle</remarks>

    <ownerSignature>
        <signatureName>/s/ Darlene Quashie Henry, as Attorney-in-Fact for William F. Doyle</signatureName>
        <signatureDate>2020-12-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
