6-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of May 2018

Commission File Number: 333-219066

Clementia Pharmaceuticals Inc.
(Translation of registrant's name into English)

4150 St Catherine Street West, Suite 550
(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.
Form 20-F [ X ]      Form 40-F [   ]

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):

Note: Regulation S-T Rule 101(b)(1) only permits the submission in paper of a Form 6-K if submitted solely to provide an attached annual report to security holders.

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Note: Regulation S-T Rule 101(b)(7) only permits the submission in paper of a Form 6-K if submitted to furnish a report or other document that the registrant foreign private issuer must furnish and make public under the laws of the jurisdiction in which the registrant is incorporated, domiciled or legally organized (the registrant's "home country"), or under the rules of the home country exchange on which the registrant's securities are traded, as long as the report or other document is not a press release, is not required to be and has not been distributed to the registrant's security holders, and, if discussing a material event, has already been the subject of a Form 6-K submission or other Commission filing on EDGAR. 

On May 2, 2018, the Registrant provided a Form of Proxy - Annual General Meeting of Shareholders which is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

(c) Exhibit 99.1. Form of Proxy - Annual General Meeting of Shareholders dated May 2, 2018

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	Clementia Pharmaceuticals Inc.
	(Registrant)
Date: May 2, 2018	/s/ MICHAEL SINGER
	Michael Singer
	Chief Financial Officer

EX-99.1

Exhibit 99.1

SecurityClass Holder AccountNumber Form of Proxy -Annual General Meeting to be held on May 29,2018 This Form of Proxy is solicited by and on behalf ofManagement. Notes toproxy 1. Every holder has the right to appoint some other person or company of their choice, who need not be a holder, to attend and act on their behalf at the meeting or any adjournment or postponement thereof. If you wish to appoint a person or company other than the persons whose names are printed herein, please insert the name of your chosen proxyholder in the space provided (seereverse). 2. If the securities are registered in the name of more than one owner (for example, joint ownership, trustees, executors, etc.), then all those registered should sign this proxy. If you are voting on behalf of a corporation or another individual you must sign this proxy with signing capacity stated, and you may be required to provide documentation evidencing your power to sign this proxy. 3. This proxy should be signed in the exact manner as the name(s) appear(s) on theproxy. 4. If this proxy is not dated, it will be deemed to bear the date on which it is mailed by Management to the holder. 5. The securities represented by this proxy will be voted as directed by the holder, however, if such a direction is not made in respect of any matter, this proxy will be voted as recommended byManagement. 6. The securities represented by this proxy will be voted in favour or withheld from voting or voted against each of the matters described herein, as applicable, in accordance with the instructions of the holder, on any ballot that may be called for and, if the holder has specified a choice with respect to any matter to be acted on, the securities will be votedaccordingly. 7. This proxy confers discretionary authority in respect of amendments or variations to matters identified in the Notice of Meeting or other matters that may properly come before the meeting or any adjournment or postponementthereof. 8. This proxy should be read in conjunction with the accompanying documentation provided byManagement. •Call the number listed BELOW from a touch tone telephone. 1-866-732-VOTE (8683) TollFree •Go to the following web site: www.investorvote.com •Smartphone? Scan the QR code to votenow. Proxies submitted must be received by 10:00 am, Eastern Time, on May 25,2018. VOTE USING THE TELEPHONE OR INTERNET 24 HOURS A DAY 7 DAYS AWEEK! To Vote Using the Telephone To Vote Using the Internet To Receive DocumentsElectronically •You can enroll to receive future securityholder communications electronically by visiting www.investorcentre.com and clicking at the bottom of thepage. If you vote by telephone or the Internet, DO NOT mail back thisproxy. Voting by mail may be the only method for securities held in the name of a corporation or securities being voted on behalf of anotherindividual. Voting by mail or by Internet are the only methods by which a holder may appoint a person as proxyholder other than the Management nominees named on the reverse of this proxy. Instead of mailing this proxy, you may choose one of the two voting methods outlined above to vote thisproxy. To vote by telephone or the Internet, you will need to provide your CONTROL NUMBER listedbelow. CONTROLNUMBER ------- Fold ------- Fold

------- Fold ------- Fold Appointment ofProxyholder I/We being holder(s) of Clementia Pharmaceuticals Inc. herebyappoint (s): Dr. Clarissa Desjardins, or failing her MichaelSinger OR Print the name of the person youare appointing if this person is someone other than the Management Nominees listedherein. Asmy/ourproxyholderwithfullpowerofsubstitutionandtoattend,actandtovoteforandonbehalfoftheshareholderinaccordancewiththefollowingdirection(orifnodirectionshavebeen given,astheproxyholderseesfit)andallothermattersthatmayproperlycomebeforetheAnnualGeneralMeetingofshareholdersofClementiaPharmaceuticalsInc.tobeheldattheoffices ofDentonsCanadaLLPlocatedat1,PlaceVille-Marie,Bureau3900,Montreal,Quebec,H3B4M7,Canada,onMay29,2018at10:00a.m.andatanyadjournmentorpostponementthereof. VOTINGRECOMMENDATIONSAREINDICATEDBYHIGHLIGHTEDTEXTOVERTHEBOXES. 1. Election ofDirectors 01. Dr. David P.Bonita For Withhold 02. Dr. ClarissaDesjardins For Withhold 03. Dr. RobertHeft For Withhold 04. Dr. FrancoisNader 05. Dr. AllanMandelzys 06. PierreLegault 07. Jean-FrancoisPariseau 2. Appointment of Auditors Appointment of KPMG LLP as Auditors of the Corporation for the ensuing year and authorizing the Directors to fix theirremuneration. For Withhold Authorized Signature(s) -This section must be completed for your instructions to beexecuted. I/We authorize you to act in accordance with my/our instructions set out above. I/We hereby revoke any proxy previously given with respect to the Meeting. If no voting instructions are indicated above, this Proxy will be voted as recommended byManagement. Signature(s) Date Interim Financial Statements -Mark this box if you would like to receive Interim Financial Statements and accompanying Management’s Discussion and Analysis by mail. Annual Financial Statements -Mark this box if you would NOT like to receive the Annual Financial Statements and accompanying Management’s Discussion and Analysis by mail. Information Circular -Mark this box if you would like to receive the Information Circular by mail for the next securityholders'meeting. If you are not mailing back your proxy, you may register online to receive the above financial report(s) by mail atwww.computershare.com/mailinglist. W W Z Q 2 7 1 8 0 5 A R2