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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-04-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001730168</issuerCik>
        <issuerName>Broadcom Inc.</issuerName>
        <issuerTradingSymbol>AVGO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001213489</rptOwnerCik>
            <rptOwnerName>EGGEBRECHT LEWIS C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BROADCOM INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1320 RIDDER PARK DRIVE</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $0.001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2018-04-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>807</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6833</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, $0.001 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Grant of Restricted Stock Units (&quot;RSUs&quot;) pursuant to the Avago Technologies Limited 2009 Equity Incentive Award Plan.  Upon vesting thereof, the Reporting Person is entitled to receive one (1) share of Issuer's common stock for each one (1) RSU.  The Vesting Commencement Date is April 4, 2018.  The RSUs vest in full on the earlier of (i) the first anniversary of the Vesting Commencement Date or (ii) the date on which the annual meeting of Issuer's stockholders immediately following the Vesting Commencement Date is held, subject to Reporting Person's continuing service on the vesting date.</footnote>
        <footnote id="F2">Includes 807 restricted stock units.</footnote>
        <footnote id="F3">Shares held by Lewis and Rebecca Eggebrecht Living Trust dated 6/21/1997 for which the Reporting Person serves as Trustee.</footnote>
    </footnotes>

    <remarks>On April 4, 2018, Broadcom Inc., a Delaware corporation, became the successor of Broadcom Limited, a company organized under the laws of the Republic of Singapore (&quot;Broadcom Limited&quot;), pursuant to a scheme of arrangement under Singapore law under which all issued ordinary shares in the capital of Broadcom Limited were exchanged on a one-for-one basis for shares of common stock of Broadcom Inc. (the &quot;Redomiciliation&quot;).  The Redomiciliation had the effect of changing Broadcom Limited's domicile, but did not alter the proportionate interests of shareholders.</remarks>

    <ownerSignature>
        <signatureName>/s/ Noelle Matteson, Attorney-in-Fact for Lewis C. Eggebrecht</signatureName>
        <signatureDate>2018-04-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
