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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-05-18</periodOfReport>

    <issuer>
        <issuerCik>0001594686</issuerCik>
        <issuerName>WASHINGTON PRIME GROUP INC.</issuerName>
        <issuerTradingSymbol>WPG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001677304</rptOwnerCik>
            <rptOwnerName>Dillon John J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WASHINGTON PRIME GROUP INC.</rptOwnerStreet1>
            <rptOwnerStreet2>180 EAST BROAD STREET</rptOwnerStreet2>
            <rptOwnerCity>COLUMBUS</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>43215</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-05-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>16000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $0.0001 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>16000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit represents a contingent right to receive one share of Washington Prime Group Inc. common stock.</footnote>
        <footnote id="F2">The restricted stock units shall vest on May 18, 2018, subject to the reporting person's continued membership on the WPG Board of Directors through that date. Vested shares will be delivered to the reporting person as soon as practicable following the cessation of membership on the Board of Directors, as provided in the Restricted Stock Unit Award Agreement.</footnote>
    </footnotes>

    <remarks>The filing of this Statement shall not be construed as an admission (a) that the person filing this Statement is, for the purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the beneficial owner of any equity securities covered by this Statement, or (b) that this Statement is legally required to be filed by such person.

Executed pursuant to Power of Attorney filed on June 22, 2016 as Exhibit 24 to Form 3.</remarks>

    <ownerSignature>
        <signatureName>/s/ Robert P. Demchak</signatureName>
        <signatureDate>2017-05-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
