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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-08-18</periodOfReport>

    <issuer>
        <issuerCik>0001258602</issuerCik>
        <issuerName>NELNET INC</issuerName>
        <issuerTradingSymbol>NNI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001269812</rptOwnerCik>
            <rptOwnerName>MUHLEISEN ANGIE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FARMERS &amp; MERCHANTS INVESTMENT INC.</rptOwnerStreet1>
            <rptOwnerStreet2>6801 SOUTH 27TH STREET</rptOwnerStreet2>
            <rptOwnerCity>LINCOLN</rptOwnerCity>
            <rptOwnerState>NE</rptOwnerState>
            <rptOwnerZipCode>68512</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isTenPercentOwner>1</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-08-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>45.34</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>526165</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By adult daughter</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-08-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>45.34</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>524708</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By adult son</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2589646</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>661093</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>175000</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Dynasty Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>175000</value>
                    <footnoteId id="F6"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Dynasty Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>174930</value>
                    <footnoteId id="F7"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>174930</value>
                    <footnoteId id="F8"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>174930</value>
                    <footnoteId id="F9"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>174930</value>
                    <footnoteId id="F10"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were sold by the reporting person's adult daughter pursuant to a Rule 10b5-1 Plan (the &quot;Daughter's Plan&quot;) entered into on March 15, 2017, which provides for the sale of shares of the issuer's Class A Common Stock, subject to limit price provisions and an expiration date.  To the extent any future sales occur pursuant to the Daughter's Plan, such sales will be publicly disclosed in Form 4 filings with the Securities and Exchange Commission (&quot;SEC&quot;).</footnote>
        <footnote id="F2">Rule 10b5-1, promulgated under the Securities Exchange Act of 1934, allows significant shareholders of a company who are not in possession of material non-public information to establish pre-arranged plans to buy or sell a specified number of shares of such company's stock.  Once a plan is established, the shareholder does not retain or exercise any discretion over sales of stock under the plan and the pre-planned trades may be executed at later dates as set forth in the plan.</footnote>
        <footnote id="F3">These shares were sold by the reporting person's adult son pursuant to a Rule 10b5-1 Plan (the &quot;Son's Plan&quot;) entered into on March 15, 2017, which provides for the sale of shares of the issuer's Class A Common Stock, subject to limit price provisions and an expiration date.  To the extent any future sales occur pursuant to the Son's Plan, such sales will be publicly disclosed in Form 4 filings with the SEC.</footnote>
        <footnote id="F4">These shares include 105,327 shares that the reporting person holds jointly with her spouse.</footnote>
        <footnote id="F5">Shares held by a Dynasty Trust, of which the adult daughter of the reporting person is the initial beneficiary.  The reporting person continues to report beneficial ownership of all the shares held by the trust, but disclaims beneficial ownership of the shares held by the trust except to the extent of the reporting person's pecuniary interest therein.</footnote>
        <footnote id="F6">Shares held by a Dynasty Trust, of which the adult son of the reporting person is the initial beneficiary. The reporting person continues to report beneficial ownership of all the shares held by the trust, but disclaims beneficial ownership of the shares held by the trust except to the extent of the reporting person's pecuniary interest therein.</footnote>
        <footnote id="F7">Shares held by the Alicia L. Muhleisen Irrevocable Trust dated 8/29/2003, of which the adult daughter of the reporting person is the beneficiary.  The reporting person continues to report beneficial ownership of all the shares held by the trust, but disclaims beneficial ownership of the shares held by the trust except to the extent of the reporting person's pecuniary interest therein.</footnote>
        <footnote id="F8">Shares held by the Jason D. Muhleisen Irrevocable Trust dated 8/29/2003, of which the adult son of the reporting person is the beneficiary. The reporting person continues to report beneficial ownership of all the shares held by the trust, but disclaims beneficial ownership of the shares held by the trust except to the extent of the reporting person's pecuniary interest therein.</footnote>
        <footnote id="F9">Shares held by the A. Muhleisen Post-Annuity Irrevocable Trust dated 8/29/2003, of which the adult son of the reporting person is the beneficiary. The reporting person continues to report beneficial ownership of all the shares held by the trust, but disclaims beneficial ownership of the shares held by the trust except to the extent of the reporting person's pecuniary interest therein.</footnote>
        <footnote id="F10">Shares held by the D. Muhleisen Post-Annuity Irrevocable Trust dated 8/29/2003, of which the adult daughter of the reporting person is the beneficiary. The reporting person continues to report beneficial ownership of all the shares held by the trust, but disclaims beneficial ownership of the shares held by the trust except to the extent of the reporting person's pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Audra Hoffschneider, Attorney-in-Fact for Angela L. Muhleisen</signatureName>
        <signatureDate>2017-08-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
