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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-01-28</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000085704</issuerCik>
        <issuerName>HARRIS TEETER SUPERMARKETS, INC.</issuerName>
        <issuerTradingSymbol>HTSI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001194591</rptOwnerCik>
            <rptOwnerName>NELSON ANNA SPANGLER</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C.D. SPANGLER CONSTRUCTION CO.</rptOwnerStreet1>
            <rptOwnerStreet2>1110 E. MOREHEAD STREET</rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTE</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>28204</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2014-01-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>49.38</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Corporation</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2014-01-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>19000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>49.38</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2014-01-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>29578</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>29578</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Pursuant to the &quot;merger agreement&quot; dated as of July 8, 2013, among Harris Teeter Supermarkets, Inc. (the &quot;Company&quot;), The Kroger Co. and Hornet Acquisition, Inc., these shares were cancelled and converted into the right to receive an amount in cash equal to $49.38 per share.</footnote>
        <footnote id="F2">The non-derivative securities indicating indirect beneficial ownership by Corporation are owned by Delcor, Inc., an affiliated corporation.</footnote>
        <footnote id="F3">The Phantom Stock Units were acquired under the Harris Teeter Supermarkets, Inc. Director Deferral Plan (the &quot;Plan&quot;).  The Company uses a non-qualified trust to purchase and hold Company stock to satisfy the Company's obligation under the Plan.  At the effective time of the merger, each current director terminated service as a member of the Company's Board of Directors, and the common stock held by the trust was cancelled and converted into the right to receive an amount in cash equal to $49.38 per share.  Such amount will be paid to the director on the 90th day following the effective day of the merger.</footnote>
        <footnote id="F4">In addition, since the Reporting Person's last report, 90 shares were acquired pursuant to the dividend reinvestment feature of the Plan.</footnote>
        <footnote id="F5">Regarding Table II, Column 8, Price of Derivative Security, for PSU, a blank or a price of $0 appears in this column.  Nonetheless, upon each deferral of annual retainer or meeting fees, the Reporting Person's account is credited with a number of PSU equal to the number of shares of HTSI that would have an aggregate fair market value (determined as of the date such retainer or fees would have been paid) equal to the amount of such retainer or fees.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Douglas J. Yacenda, attorney-in-fact for Anna Spangler Nelson</signatureName>
        <signatureDate>2014-01-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
