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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-01-13</periodOfReport>

    <issuer>
        <issuerCik>0000108772</issuerCik>
        <issuerName>XEROX CORP</issuerName>
        <issuerTradingSymbol>XRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001575440</rptOwnerCik>
            <rptOwnerName>CHRISTODORO JONATHAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ICAHN CAPITAL LP</rptOwnerStreet1>
            <rptOwnerStreet2>767 FIFTH AVENUE, SUITE 4700</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10153</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Deferred Stock Units</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2017-01-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12803</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7.03</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21700</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Each DSU represent the right to receive one share of common stock upon the reporting person's termination of service as a director.</footnote>
        <footnote id="F2">This amount includes 68 shares paid on 10/29/16 from the reinvestment of dividend equivalents paid on Deferred Stock Units held as of 9/30/2016. These dividend equivalents have been adjusted to reflect the effects of separation.</footnote>
        <footnote id="F3">Reflects an antidilution adjustment to the number of DSUs that was made in connection with the legal and structural separation (the &quot;Spin-Off&quot;) of Conduent Incorporated from Xerox Corporation (&quot;Xerox&quot;). The number of shares of Xerox's common stock subject to the awards was adjusted based on the number of the shares subject to the DSU awards immediately prior to the Spin-Off and (ii) the ratio of (A) the pre-Spin-Off closing price on December 30, 2016 of Xerox's common stock and (B ) the volume weighted average price of Xerox's common stock trading on the New York Stock Exchange on January 3, 2017.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Karen Boyle, Attorney in Fact</signatureName>
        <signatureDate>2017-01-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
