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

    <schemaVersion>X0708</schemaVersion>

    <submissionType>D</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0001657352</cik>
        <entityName>Terrestrial Energy Inc.</entityName>
        <issuerAddress>
            <street1>2275 UPPER MIDDLE ROAD EAST</street1>
            <street2>SUITE 201</street2>
            <city>OAKVILLE</city>
            <stateOrCountry>A6</stateOrCountry>
            <stateOrCountryDescription>ONTARIO, CANADA</stateOrCountryDescription>
            <zipCode>L6H 0C3</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>646-236-4735</issuerPhoneNumber>
        <jurisdictionOfInc>ONTARIO, CANADA</jurisdictionOfInc>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <edgarPreviousNameList>
            <value>None</value>
        </edgarPreviousNameList>
        <entityType>Corporation</entityType>
        <yearOfInc>
            <overFiveYears>true</overFiveYears>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>SIMON</firstName>
                <lastName>IRISH</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>2275 UPPER MIDDLE ROAD EAST</street1>
                <street2>SUITE 201</street2>
                <city>OAKVILLE</city>
                <stateOrCountry>A6</stateOrCountry>
                <stateOrCountryDescription>ONTARIO, CANADA</stateOrCountryDescription>
                <zipCode>L6H 0C3</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
                <relationship>Director</relationship>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>DAVID</firstName>
                <lastName>LEBLANC</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>2275 UPPER MIDDLE ROAD EAST</street1>
                <street2>SUITE 201</street2>
                <city>OAKVILLE</city>
                <stateOrCountry>A6</stateOrCountry>
                <stateOrCountryDescription>ONTARIO, CANADA</stateOrCountryDescription>
                <zipCode>L6H 0C3</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>CANON</firstName>
                <lastName>BRYAN</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>2275 UPPER MIDDLE ROAD EAST</street1>
                <street2>SUITE 201</street2>
                <city>OAKVILLE</city>
                <stateOrCountry>A6</stateOrCountry>
                <stateOrCountryDescription>ONTARIO, CANADA</stateOrCountryDescription>
                <zipCode>L6H 0C3</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>HUGH</firstName>
                <lastName>MACDIARMID</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>2275 UPPER MIDDLE ROAD EAST</street1>
                <street2>SUITE 201</street2>
                <city>OAKVILLE</city>
                <stateOrCountry>A6</stateOrCountry>
                <stateOrCountryDescription>ONTARIO, CANADA</stateOrCountryDescription>
                <zipCode>L6H 0C3</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>DAVID</firstName>
                <lastName>HILL</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>2275 UPPER MIDDLE ROAD EAST</street1>
                <street2>SUITE 201</street2>
                <city>OAKVILLE</city>
                <stateOrCountry>A6</stateOrCountry>
                <stateOrCountryDescription>ONTARIO, CANADA</stateOrCountryDescription>
                <zipCode>L6H 0C3</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>FRED</firstName>
                <lastName>BUCKMAN</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>2275 UPPER MIDDLE ROAD EAST</street1>
                <street2>SUITE 201</street2>
                <city>OAKVILLE</city>
                <stateOrCountry>A6</stateOrCountry>
                <stateOrCountryDescription>ONTARIO, CANADA</stateOrCountryDescription>
                <zipCode>L6H 0C3</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Other Energy</industryGroupType>
        </industryGroup>
        <issuerSize>
            <revenueRange>Decline to Disclose</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06b</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>false</isAmendment>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2023-09-01</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>false</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isOtherType>true</isOtherType>
            <descriptionOfOtherType>Convertible Bond with warrant</descriptionOfOtherType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>1</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>Indefinite</totalOfferingAmount>
            <totalAmountSold>4326000</totalAmountSold>
            <totalRemaining>Indefinite</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>16</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
            <clarificationOfResponse></clarificationOfResponse>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>100000</dollarAmount>
                <isEstimate>true</isEstimate>
            </grossProceedsUsed>
            <clarificationOfResponse></clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>Terrestrial Energy Inc.</issuerName>
                <signatureName>Simon Irish</signatureName>
                <nameOfSigner>SIMON IRISH</nameOfSigner>
                <signatureTitle>CHIEF EXECUTIVE OFFICER</signatureTitle>
                <signatureDate>2023-10-17</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
