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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-06-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000107140</issuerCik>
        <issuerName>WILEY JOHN &amp; SONS, INC.</issuerName>
        <issuerTradingSymbol>jwa</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001201958</rptOwnerCik>
            <rptOwnerName>MELANDO EDWARD J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O JOHN WILEY &amp; SONS INC</rptOwnerStreet1>
            <rptOwnerStreet2>111 RIVER STREET</rptOwnerStreet2>
            <rptOwnerCity>HOBOKEN</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07030</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP, Corporate Controller</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common</value>
            </securityTitle>
            <transactionDate>
                <value>2009-06-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13108</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Non-Qualified Options</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-06-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6900</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2013-04-30</value>
            </exerciseDate>
            <expirationDate>
                <value>2019-06-10</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6900</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6900</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Performance-based award subject to adjustment at the end of the three-year cycle based on financial performance, and subject to forfeiture until vested.</footnote>
        <footnote id="F2">Closing price of Class A Common Stock pursuant to NYSE on June 25, 2009.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Josephine Bacchi for Edward Melando</signatureName>
        <signatureDate>2009-06-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0303
4
2009-06-15
0
0000107140
WILEY JOHN & SONS, INC.
jwa
0001201958
MELANDO EDWARD J
C/O JOHN WILEY & SONS INC
111 RIVER STREET
HOBOKEN
NJ
07030
0
1
0
0
VP, Corporate Controller
Class A Common
2009-06-11
4
A
0
2300
A
13108
D
Non-Qualified Options
2009-06-11
4
A
0
6900
A
2013-04-30
2019-06-10
Class A Common
6900
6900
D
Performance-based award subject to adjustment at the end of the three-year cycle based on financial performance, and subject to forfeiture until vested.
Closing price of Class A Common Stock pursuant to NYSE on June 25, 2009.
Josephine Bacchi for Edward Melando
2009-06-15