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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-03-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001227073</issuerCik>
        <issuerName>WELLS FARGO MULTI-SECTOR INCOME FUND</issuerName>
        <issuerTradingSymbol>ERC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001510281</rptOwnerCik>
            <rptOwnerName>Saba Capital Management, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>405 LEXINGTON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>58TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10174</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001608233</rptOwnerCik>
            <rptOwnerName>Weinstein Boaz</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>405 LEXINGTON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>58TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10174</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-03-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>11600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.09</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5359778</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes 1 and 2</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The securities reported herein are held by (i) Saba Capital Master Fund, Ltd., a Cayman Islands exempted company
(ii) Saba Capital Master Fund II, Ltd., a Cayman Islands exempted company, (iii) Saba Capital Leveraged Master Fund, Ltd., a Cayman
Islands exempted company, (iv) Saba Capital Series LLC Series 1, a Delaware series limited liability company, (v) Saba Capital CEF Opportunities 1 Ltd., a Cayman Islands exempted company,
(vi) Saba Capital CEF Opportunities 2, Ltd., a Cayman Islands exempted company.  Collectively, the &quot;Saba Funds&quot;.</footnote>
        <footnote id="F2">Mr. Boaz R. Weinstein (&quot;Mr. Weinstein&quot;) serves as the managing member of Saba Capital Management GP, LLC, the general
partner of Saba Capital Management, L.P., a Delaware limited partnership (&quot;Saba Capital&quot;). Saba Capital serves as the investment
manager of the Saba Funds. Each Reporting Person disclaims beneficial ownership of the securities reported herein except to the
extent of his or its pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Muqu Karim</signatureName>
        <signatureDate>2016-03-24</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Boaz Weinstein</signatureName>
        <signatureDate>2016-03-24</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>William Manzolillo</signatureName>
        <signatureDate>2016-03-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
