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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2019-12-06</periodOfReport>

    <dateOfOriginalSubmission>2019-12-10</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000092230</issuerCik>
        <issuerName>TRUIST FINANCIAL CORP</issuerName>
        <issuerTradingSymbol>TFC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001789902</rptOwnerCik>
            <rptOwnerName>Maguire Michael Baron</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>214 N. TRYON STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTE</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>28202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-12-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2891</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2020-02-14</value>
            </exerciseDate>
            <expirationDate>
                <value>2020-02-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2891</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2891</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2020-02-14</value>
            </exerciseDate>
            <expirationDate>
                <value>2020-02-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2891</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2891</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2022-02-08</value>
            </exerciseDate>
            <expirationDate>
                <value>2022-02-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7349</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7349</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Pursuant to the Agreement and Plan of Merger by and between SunTrust Banks, Inc. (&quot;SunTrust&quot;) and BB&amp;T Corporation (&quot;BB&amp;T&quot;), dated February 7, 2019 and amended as of June 14, 2019 (the &quot;Merger Agreement&quot;), SunTrust was merged with and into BB&amp;T, effective December 6, 2019 (the &quot;Merger&quot;). Pursuant to the Merger, each issued and outstanding share of SunTrust common stock was converted into the right to receive 1.295 shares of BB&amp;T common stock. The closing price of BB&amp;T common stock on the New York Stock Exchange on the effective date of the Merger was $54.24. Following and in connection with the Merger, BB&amp;T changed its name to Truist Financial Corporation (&quot;Truist&quot;). These stock units represent time-vested restricted stock units, each convertible into one share of common stock, under the SunTrust Banks, Inc. 2009 Stock Plan or the SunTrust Banks, Inc. 2018 Omnibus Incentive Compensation Plan.</footnote>
        <footnote id="F2">(Continued from Footnote 1) Pursuant to the Merger Agreement, at the effective time of the Merger, each outstanding SunTrust time-vested restricted stock unit automatically converted into a BB&amp;T time-vested restricted stock unit convertible into shares of BB&amp;T common stock, with the number of underlying shares of BB&amp;T common stock determined as set forth in the Merger Agreement. Following and in connection with the Merger, BB&amp;T changed its name to Truist. Each Truist time-vested restricted stock unit is subject to the same terms and conditions (including vesting terms) as applied to the corresponding SunTrust time-vested restricted stock unit immediately prior to the effective time of the Merger.</footnote>
        <footnote id="F3">These time-vested restricted stock units replaced SunTrust time-vested restricted stock units in respect of an aggregate 2,231.797 shares of SunTrust common stock.</footnote>
    </footnotes>

    <remarks>This Amendment is being filed to report a transaction that was inadvertently omitted from the original, which transaction is shown in the first row of Table II above. The other two holdings are not new holdings but restated holdings to report the accurate balance due to rounding.</remarks>

    <ownerSignature>
        <signatureName>Carla Brenwald, Attorney-in-Fact</signatureName>
        <signatureDate>2020-01-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
