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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

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

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001724670</issuerCik>
        <issuerName>Perspecta Inc.</issuerName>
        <issuerTradingSymbol>PRSP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001360891</rptOwnerCik>
            <rptOwnerName>Musallam Ramzi M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VERITAS CAPITAL FUND MANAGEMENT, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>9 WEST 57TH STREET, 29TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001742035</rptOwnerCik>
            <rptOwnerName>SI Organization Holdings LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VERITAS CAPITAL FUND MANAGEMENT, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>9 WEST 57TH STREET, 29TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001469805</rptOwnerCik>
            <rptOwnerName>Veritas Capital Fund IV, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VERITAS CAPITAL FUND MANAGEMENT, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>9 WEST 57TH STREET, 29TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001591823</rptOwnerCik>
            <rptOwnerName>Veritas Capital Partners IV, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VERITAS CAPITAL FUND MANAGEMENT, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>9 WEST 57TH STREET, 29TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>23273341</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 3 is filed jointly by Ramzi M. Musallam, The SI Organization Holdings LLC (&quot;The SI LLC&quot;), The Veritas Capital Fund IV, L.P. (&quot;Fund IV&quot;) and Veritas Capital Partners IV, L.L.C. (&quot;Fund IV LLC&quot;) (collectively, the &quot;Reporting Persons&quot;). The shares of Common Stock, par value $0.01 per share (&quot;Common Stock&quot;) of Perspecta Inc. (&quot;Issuer&quot;) are directly owned by The SI LLC and KGS Holding LLC (&quot;KGS LLC&quot;). The SI LLC directly owns 18,877,244 shares of Common Stock and KGS LLC directly owns 4,396,097 shares of Common Stock. Fund IV may be deemed a beneficial owner of shares of Common Stock directly owned by The SI LLC, including on the basis of its power to appoint all of the members of the board of managers of The SI LLC. Fund IV LLC may be deemed a beneficial owner of shares of Common Stock directly owned by The SI LLC, including on the basis of Fund IV LLC serving as the general partner of Fund IV.</footnote>
        <footnote id="F2">(Continued from Footnote 1) Ramzi M. Musallam may be deemed a beneficial owner of shares of Common Stock directly owned by The SI LLC, and shares of Common Stock directly owned by KGS LLC, including on the basis of Mr. Musallam serving as the managing partner of Fund IV LLC and as the managing partner of Veritas Capital Partners III, L.L.C., which is the general partner of The Veritas Capital Fund III, L.P., which is the managing member of KGS LLC. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of his or its pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Ramzi M. Musallam</signatureName>
        <signatureDate>2018-06-06</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Ramzi M. Musallam, Authorized Signatory for The Veritas Capital Fund IV, L.P., acting as the Majority of Members of The SI Organization Holdings LLC</signatureName>
        <signatureDate>2018-06-06</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Ramzi M. Musallam, Managing Partner of Veritas Capital Partners IV, L.L.C., General Partner of The Veritas Capital Fund IV, L.P.</signatureName>
        <signatureDate>2018-06-06</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Ramzi M. Musallam, Managing Partner of Veritas Capital Partners IV, L.L.C.</signatureName>
        <signatureDate>2018-06-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
