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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2018-05-31</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001267238</issuerCik>
        <issuerName>ASSURANT INC</issuerName>
        <issuerTradingSymbol>AIZ</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001741084</rptOwnerCik>
            <rptOwnerName>McGoohan Peter</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TPG GLOBAL, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>301 COMMERCE STREET, SUITE 3300</rptOwnerStreet2>
            <rptOwnerCity>FORT WORTH</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>76102</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>No securities beneficially owned</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Peter McGoohan is a TPG Principal. TPG is affiliated with each of (i) TPG VI Wolverine, LP (&quot;TPG VI Wolverine&quot;), which directly holds 4,697,702 shares of Common Stock (&quot;Common Stock&quot;) of Assurant, Inc. (the &quot;Issuer&quot;), and (ii) TPG VI Wolverine Co-Invest, LP (&quot;TPG VI Wolverine Co-Invest&quot; and, together with TPG VI Wolverine, the &quot;TPG Funds&quot;), which directly holds 5,371,528 shares of Common Stock.</footnote>
        <footnote id="F2">Mr. McGoohan disclaims beneficial ownership of all of the securities that are or may be beneficially owned by the TPG Funds or any of their affiliates. Pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;), this filing shall not be deemed an admission that Mr. McGoohan is, for purposes of Section 16 of the Exchange Act or otherwise, the beneficial owner of any equity securities of the Issuer for purposes of Section 16 of the Exchange Act or otherwise.</footnote>
    </footnotes>

    <remarks>(3) Adam Fliss is signing on behalf of Mr. McGoohan pursuant to the authorization and designation letter dated May 11, 2018, which is attached here as an exhibit.</remarks>

    <ownerSignature>
        <signatureName>/s/ Adam Fliss on behalf of Peter McGoohan (3)</signatureName>
        <signatureDate>2018-06-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
