UNITED STATESSECURITIES AND EXCHANGE ~~COMMISSION Washington~~COMMISSIONWashington, D.C. ~~20549____________________~~20549

~~FORM~~Form 6-~~K____________________~~K

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

For the month of ~~March~~April 2019

Commission File Number: ~~001~~333-~~38177____________________~~219066

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

1000 de la ~~Gauchetière~~Gauchetiere Street West, Suite ~~1200~~1200Montreal, ~~Montreal,~~ Quebec, CANADA , H3B 4W5~~, Canada~~ (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 [ ]

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):

~~DOCUMENTS~~Note: Regulation ~~FURNISHED~~S-T ASRule ~~PART~~101(b)(7) OFonly ~~THIS~~permits ~~FORM~~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.

AThe ~~Notice~~information ofcontained ~~Special~~in ~~Meeting~~this ofReport ~~Shareholders~~(including ~~and~~the ~~Management~~exhibits ~~Information~~hereto) ~~Circular~~is hereby incorporated by reference into Clementia Pharmaceuticals Inc.’s Registration Statement on Form F-3 (File No. 333-227726).

~~Form~~On April 9, 2019, the Registrant issued a press release, a copy of ~~Proxy~~which ~~for~~is ~~Registered~~attached ~~Shareholders~~hereto as Exhibit 99.1 and is incorporated herein by reference. (c) Exhibit 99.1. Press release dated April 9, 2019

A Letter of Transmittal

Exhibits 99.1 – Notice of Special Meeting of Shareholders and Management Information Circular 99.2 – Form of Proxy for Registered Shareholders 99.3 – Letter of Transmittal

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.~~	Clementia Pharmaceuticals Inc.
	~~(Registrant)~~	(Registrant)
Date: March 13, 2019	By:	/s/ Steve Forte
Date: April 9, 2019		/s/ Steve Forte
		Steve Forte
		Chief Financial Officer

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