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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-12-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000104889</issuerCik>
        <issuerName>Graham Holdings Co</issuerName>
        <issuerTradingSymbol>GHC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001501808</rptOwnerCik>
            <rptOwnerName>Weymouth Katharine</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1300 NORTH 17TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1700</rptOwnerStreet2>
            <rptOwnerCity>ARLINGTON</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22209</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>668</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>930.37</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19053</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>931.81</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18753</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>431</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>932.87</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18322</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1465</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>934.66</value>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16857</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>502</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>935.82</value>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16355</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>707</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>936.32</value>
                    <footnoteId id="F6"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15648</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>845</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>937.91</value>
                    <footnoteId id="F7"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14803</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>82</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>938.61</value>
                    <footnoteId id="F8"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14721</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $930.00 to $930.90, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $931.43 to $932.00, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.</footnote>
        <footnote id="F3">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $932.45 to $933.01, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.</footnote>
        <footnote id="F4">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $934.00 to $935.00, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.</footnote>
        <footnote id="F5">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $935.02 to $936.01, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.</footnote>
        <footnote id="F6">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $936.12 to $936.75, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.</footnote>
        <footnote id="F7">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $937.20 to $938.12, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.</footnote>
        <footnote id="F8">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $938.60 to $938.63, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Katharine Weymouth</signatureName>
        <signatureDate>2014-12-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0306
4
2014-12-09
0
0000104889
Graham Holdings Co
GHC
0001501808
Weymouth Katharine
1300 NORTH 17TH STREET
SUITE 1700
ARLINGTON
VA
22209
1
0
0
0
Class B Common Stock
2014-12-09
4
S
0
668
930.37
D
19053
D
Class B Common Stock
2014-12-09
4
S
0
300
931.81
D
18753
D
Class B Common Stock
2014-12-09
4
S
0
431
932.87
D
18322
D
Class B Common Stock
2014-12-09
4
S
0
1465
934.66
D
16857
D
Class B Common Stock
2014-12-09
4
S
0
502
935.82
D
16355
D
Class B Common Stock
2014-12-09
4
S
0
707
936.32
D
15648
D
Class B Common Stock
2014-12-09
4
S
0
845
937.91
D
14803
D
Class B Common Stock
2014-12-09
4
S
0
82
938.61
D
14721
D
The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $930.00 to $930.90, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.
The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $931.43 to $932.00, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.
The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $932.45 to $933.01, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.
The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $934.00 to $935.00, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.
The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $935.02 to $936.01, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.
The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $936.12 to $936.75, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.
The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $937.20 to $938.12, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.
The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $938.60 to $938.63, inclusive. The reporting person undertakes to provide to Graham Holdings Company, any security holder of Graham Holdings Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the shares sold.
Katharine Weymouth
2014-12-11