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

    <schemaVersion>X0205</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2012-06-01</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000911421</issuerCik>
        <issuerName>PARTNERRE LTD</issuerName>
        <issuerTradingSymbol>PRE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001551336</rptOwnerCik>
            <rptOwnerName>Willam Egbert P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>WILHELM-VON-CAPITAINE-STR</rptOwnerStreet1>
            <rptOwnerStreet2>5</rptOwnerStreet2>
            <rptOwnerCity>COLOGNE</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>Jean-Paul Dyer as Attorney-in-Fact for Egbert Willam</signatureName>
        <signatureDate>2012-06-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
