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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-02-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001083301</issuerCik>
        <issuerName>TERAWULF INC.</issuerName>
        <issuerTradingSymbol>WULF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001897085</rptOwnerCik>
            <rptOwnerName>Pascual Bryan J.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>53 PALMERAS STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 601</rptOwnerStreet2>
            <rptOwnerCity>SAN JUAN</rptOwnerCity>
            <rptOwnerState>PR</rptOwnerState>
            <rptOwnerZipCode>00901</rptOwnerZipCode>
            <rptOwnerStateDescription>PUERTO RICO</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001885426</rptOwnerCik>
            <rptOwnerName>Bayshore Capital LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>53 PALMERAS STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 601</rptOwnerStreet2>
            <rptOwnerCity>SAN JUAN</rptOwnerCity>
            <rptOwnerState>PR</rptOwnerState>
            <rptOwnerZipCode>00901</rptOwnerZipCode>
            <rptOwnerStateDescription>PUERTO RICO</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, $0.001 par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2023-02-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2157006</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18083348</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By LLC</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series A Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>250000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Warrants to Purchase Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.93</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2022-10-06</value>
            </exerciseDate>
            <expirationDate>
                <value>2027-10-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1587302</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1587302</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By LLC</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeTransaction>
            <securityTitle>
                <value>Convertible Promissory Note</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2023-02-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionTotalValue>
                    <value>862802</value>
                </transactionTotalValue>
                <transactionPricePerShare>
                    <value>862802</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2023-02-28</value>
            </exerciseDate>
            <expirationDate>
                <value>2025-04-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>862802</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By LLC</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Convertible Promissory Note</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2023-02-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionTotalValue>
                    <value>862802</value>
                </transactionTotalValue>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2023-02-28</value>
            </exerciseDate>
            <expirationDate>
                <value>2025-04-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2157006</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By LLC</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On November 25, 2022, Bayshore (defined below) purchased from the Issuer a Convertible Promissory Note with an aggregate original principal amount of $853,912.33 (as subsequently amended, the &quot;Convertible Note&quot;), which initially did not have a fixed conversion price and therefore was not a derivative security within the meaning of Rule 16a-1 under the Securities Exchange Act of 1934, as amended, at the time of the purchase.</footnote>
        <footnote id="F2">As amended, the Convertible Note accrued annual interest at a rate of 4% and was automatically convertible into equity securities of the Issuer on the third business day (the &quot;Conversion Date&quot;) following the date on which stockholder approval of an increase in the Issuer's authorized Common Stock (defined below) is obtained (the &quot;Stockholder Approval&quot;) at a conversion price equal to the lowest price per share paid by investors purchasing equity securities in any sale of equity securities by the Issuer between the issuance date of the Convertible Note and the Conversion Date with an aggregate gross sales price of not less than $5 million, subject to certain exclusions set forth in the Convertible Note (a &quot;Qualified Financing&quot;).</footnote>
        <footnote id="F3">On February 23, 2023, the Issuer received the Stockholder Approval and on February 28, 2023, the Conversion Date, the entire aggregate principal amount of the Convertible Note and approximately $8,890 of accrued but unpaid interest thereon was converted into an aggregate of 2,157,006 shares of Common Stock based on a conversion price of $0.40, which represents the lowest price per share paid by investors in a Qualified Financing.</footnote>
        <footnote id="F4">The reported shares of common stock, $0.001 par value per share, of the Issuer (&quot;Common Stock&quot;), and warrants to purchase Common Stock are held Bayshore Capital LLC (&quot;Bayshore&quot;). The BJP Revocable Trust dated December 10, 2021 (the &quot;Trust&quot;) is the sole member of Bayshore. Mr. Bryan Pascual is the sole trustee and sole lifetime beneficiary of the Trust and may be deemed to beneficially own the Issuer securities held by the Trust. Each of Bayshore, the Trust and Mr. Pascual disclaims beneficial ownership of such securities except to the extent of their respective pecuniary interest therein, and the inclusion of such securities in this report shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
        <footnote id="F5">Each holder of shares of the Issuer's Series A Convertible Preferred Stock (the &quot;Preferred Stock&quot;) has the right, at its option and at any time, to convert all or a portion of the shares of Preferred Stock that it holds into a number of shares of Common Stock equal to the quotient obtained by dividing (i) the sum of (x) the Liquidation Preference (as defined in the Certificate of Designations governing the Preferred Stock, initially $1,000) and (y) an amount equal to accumulated and unpaid Regular Dividends (as defined in the Certificate of Designations) on such shares of Preferred Stock, by (ii) the Conversion Price (as defined in the Certificate of Designations) in effect at such time, subject to customary antidilution adjustments, including in the event of any stock split, stock dividend, recapitalization or similar events.</footnote>
        <footnote id="F6">As of the date of the acquisition of the Preferred Stock, the 2,500 shares of Preferred Stock reported on this report were convertible into 250,000 shares of Common Stock. The Preferred Stock does not expire.</footnote>
        <footnote id="F7">The reported shares of Preferred Stock are held by the Trust. Mr. Bryan Pascual is the sole trustee and sole lifetime beneficiary of the Trust and may be deemed to beneficially own the shares of Preferred Stock held by the Trust. Each of the Trust and Mr. Pascual disclaims beneficial ownership of such shares except to the extent of their respective pecuniary interest therein, and the inclusion of such shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Bryan J. Pascual</signatureName>
        <signatureDate>2023-03-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Bryan J. Pascual, as Trustee for the BJP Revocable Trust, as sole member of Bayshore Capital LLC</signatureName>
        <signatureDate>2023-03-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
