As filed with the Securities and Exchange Commission on
March 16, 2018
Registration No. 33-35576
811-06128
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
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FORM N-1A
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REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	/ X /
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Pre-Effective Amendment No.	/    /
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Post-Effective Amendment No. 39	/ X /
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REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY	/ X /
ACT OF 1940	----
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Amendment No. 40	/ X /
(Check appropriate box or boxes)	----
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PUTNAM SUSTAINABLE LEADERS FUND
(Exact Name of Registrant as Specified in Charter)
One Post Office Square, Boston, Massachusetts 02109
(Address of Principal Executive Offices) (Zip Code)
Registrant's Telephone Number, including Area Code
(617) 292-1000
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	It is proposed that this filing will become effective
	(check appropriate box)
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/    /	immediately upon filing pursuant to paragraph (b)
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/ x /	on March 21, 2018 pursuant to paragraph (b)
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/    /	60 days after filing pursuant to paragraph (a)(1)
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/    /	on (date) pursuant to paragraph (a)(1)
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/    /	75 days after filing pursuant to paragraph (a)(2)
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/    /	on (date) pursuant to paragraph (a)(2) of Rule 485.
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If appropriate, check the following box:
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/ x /	this post-effective amendment designates a new
----	effective date for a previously filed post-effective amendment.
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	ROBERT T. BURNS, Vice President
	PUTNAM SUSTAINABLE LEADERS FUND
	One Post Office Square
	Boston, Massachusetts 02109
	(Name and address of agent for service)
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	Copy to:
	BRYAN CHEGWIDDEN, Esquire
	ROPES & GRAY LLP
	1211 Avenue of the Americas
	New York, New York 10036
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This Post-Effective Amendment No. 39 is being filed pursuant to Rule 485(b) under the Securities Act of 1933, as amended (the “Securities Act”), solely to designate March 21, 2018, as the new effective date for Post-Effective Amendment No. 38 filed pursuant to Rule 485(a) under the Securities Act on January 18, 2018. This Post-Effective Amendment No. 39 is not intended to amend or supersede any information contained in Post-Effective Amendment No. 38.

PUTNAM SUSTAINABLE LEADERS FUND 

Part A. INFORMATION REQUIRED IN A PROSPECTUS

Part A is incorporated by reference to Part A of Post-Effective Amendment No. 38 to the Registration Statement on Form N-1A of Putnam Sustainable Leaders Fund (formerly Putnam Multi-Cap Growth Fund) (the “Registrant”) under the Securities Act of 1933, as amended, and Amendment No. 39 to the Registrant’s Registration Statement on Form N-1A under the Investment Company Act of 1940, as amended, filed with the Securities and Exchange Commission (the “SEC”) on January 18, 2018 (“Amendment No. 38/39”).

Part B. INFORMATION REQUIRED IN A STATEMENT OF ADDITIONAL INFORMATION

Part B is incorporated by reference to Part B of Amendment No. 38/39 to the Registrant’s Registration Statement on Form N-1A filed with the SEC on January 18, 2018.

Part C. OTHER INFORMATION

Part C is incorporated by reference to Part C of Amendment No. 38/39 to the Registrant’s Registration Statement on Form N-1A filed with the SEC on January 18, 2018.

SIGNATURES 

Pursuant to the requirements of the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all of the requirements for effectiveness of this Registration Statement under Rule 485(b) under the Securities Act of 1933, as amended, and the Registrant has duly caused this Amendment to its Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of Boston, and The Commonwealth of Massachusetts, on the 16^th day of March, 2018.

Putnam Sustainable Leaders Fund 

By: /s/ Jonathan S. Horwitz, Executive Vice President, 

Principal Executive Officer and Compliance Liaison 

Pursuant to the requirements of the Securities Act of 1933, as amended, this Amendment to the Registration Statement has been signed below by the following persons in the capacities and on the date indicated:

Signature	Title
Jameson A. Baxter *	Chair, Board of Trustees
Kenneth R. Leibler*	Vice Chair, Board of Trustees

Robert L. Reynolds*	President and Trustee
Jonathan S. Horwitz*	Executive Vice President, Principal Executive
	Officer and Compliance Liaison
Janet C. Smith*	Vice President, Principal Financial Officer,
	Principal Accounting Officer and Assistant
	Treasurer
Liaquat Ahamed*	Trustee
Ravi Akhoury*	Trustee
Barbara M. Baumann*	Trustee
Katinka Domotorffy*	Trustee
Catharine Bond Hill*	Trustee
Paul L. Joskow*	Trustee
Robert E. Patterson*	Trustee
George Putnam, III*	Trustee
Manoj P. Singh*	Trustee

By: /s/ Jonathan S. Horwitz, as 

Attorney-in-Fact 

March 16, 2018 

* Signed pursuant to power of 

attorney filed in Post-Effective 

Amendment No. 36 to the 

Registrant’s Registration Statement 

on October 27, 2017.