245 Summer Street

Fidelity® Investments

Boston, MA 02210

July 31, 2024

U.S. Securities & Exchange Commission

100 F Street, N.E.

Washington, D.C. 20549

Attention: File Room

RE: Fidelity Summer Street Trust (the trust): File Nos. 002-58542 and 811-02737 Fidelity Agricultural Productivity Fund Fidelity Climate Action Fund Fidelity SAI Sustainable Future Fund Fidelity SAI Sustainable Sector Fund Fidelity SAI Sustainable U.S. Equity Fund Fidelity Sustainable U.S. Equity Fund Fidelity Water Sustainability Fund (the fund(s))

________________________________________________________________________

Ladies and Gentlemen:

Transmitted herewith pursuant to Rule 497(j) under the Securities Act of 1933 is certification that the Prospectus(es) and Statement(s) of Additional Information with respect to the above referenced fund(s) do not differ from those filed in the most recent post-effective amendment, which was filed electronically.

Very truly yours,

/s/Margaret Carey

Margaret Carey

Secretary of the Trust