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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-10-27</periodOfReport>

    <issuer>
        <issuerCik>0001331875</issuerCik>
        <issuerName>Fidelity National Financial, Inc.</issuerName>
        <issuerTradingSymbol>FNF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001663155</rptOwnerCik>
            <rptOwnerName>Nolan Michael Joseph</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>601 RIVERSIDE AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>JACKSONVILLE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>32204</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>FNF Group Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-10-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7518</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>36.84</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>131195.7604</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>FNF Group Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>26221.025</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Michael J. Nolan Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>FNF Group Stock Option (right To Purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>21.84</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2015-11-03</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2021-11-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>FNF Group Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>75608</value>
                    <footnoteId id="F4"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>75608</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>FNF Group Stock Option (right To Purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>25.53</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2016-10-29</value>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <value>2022-10-29</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>FNF Group Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>116014</value>
                    <footnoteId id="F4"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>116014</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>FNF Group Stock Option (right To Purchase)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>17.76</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2014-11-21</value>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2020-11-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>FNF Group Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>75884</value>
                    <footnoteId id="F4"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>75884</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">As a result of an anti-dilution adjustment made in connection with the spinoff of Black Knight Financial Services, Inc. from the registrant, the number of shares subject to each outstanding FNF Group restricted stock award was increased to include an additional number of restricted shares of FNF Group common stock with an initial value equal to the value of Black Knight, Inc. common stock the holder would have otherwise received.  The number of additional shares of FNF Group common stock was determined using the volume weighted average prices of FNF Group common stock and Black Knight, Inc. common stock over the three trading days immediately following the spin-off.  Restricted stock awards were rounded down to the nearest share and cash was issued in lieu of fractional restricted shares.</footnote>
        <footnote id="F2">Amount adjusted to reflect shares acquired under the registrant's Employee Stock Purchase Plan.</footnote>
        <footnote id="F3">The options vested in three equal annual installments beginning November 3, 2015 .</footnote>
        <footnote id="F4">As a result of an anti-dilution adjustment made in connection with the spinoff of Black Knight Financial Services, Inc. from the registrant, the number of shares and exercise prices of each outstanding FNF Group stock option award were adjusted to preserve the award's pre-spinoff intrinsic value using (i) the volume weighted average price of FNF Group common stock over the three trading days immediately preceding the spinoff, and (ii) the volume weighted average price of FNF Group common stock over the three days immediately following the spinoff.  Stock options were rounded down to the nearest share and up to the nearest penny, and cash was issued in lieu of options to purchase fractional shares.</footnote>
        <footnote id="F5">The options vest in three equal annual installments beginning October 29, 2016.</footnote>
        <footnote id="F6">The options vested in three equal annual installments beginning November 21, 2014.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Colleen E. Haley, as attorney-in-fact</signatureName>
        <signatureDate>2017-10-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
