Form 485BXT BLACKROCK LIQUIDITY FUND

As filed with the Securities and Exchange Commission on July 29, 2026

1933 Act Registration No. 2-47015

1940 Act Registration No. 811-2354

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM N-1A

BLACKROCK LIQUIDITY FUNDS

(Exact Name of Registrant as Specified in Charter)

100 Bellevue Parkway, Wilmington, Delaware 19809

United States of America

(Address of Principal Executive Offices)

Registrant’s Telephone Number, including Area Code: (800) 441-7450

John M. Perlowski

BLACKROCK LIQUIDITY FUNDS

50 Hudson Yards

New York, New York 10001

United States of America

(Name and Address of Agent for Service)

Copies to:

It is proposed that this filing will become effective (check appropriate box):

If appropriate, check the following box:

Title of Securities Being Registered: Shares of Beneficial Interest, par value $0.001 per share.

Explanatory Note

This Post-Effective Amendment No. 160 under the Securities Act of 1933, as amended (the “Securities Act”) to the registration statement on Form N-1A (the “Registration Statement”) of BlackRock Liquidity Funds (the “Registrant”) is being filed pursuant to paragraph (b)(1)(iii) of Rule 485 under the Securities Act solely for the purpose of delaying, until July  31, 2026, the effectiveness of the registration statement of BlackRock Select Treasury Based Liquidity Fund, filed in Post-Effective Amendment No. 158 on May 8, 2026, pursuant to paragraph (a) of Rule 485 under the Securities Act.

This Post-Effective Amendment No. 160 incorporates by reference the information contained in Post-Effective Amendment No. 158 to the Registrant’s Registration Statement.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all the requirements for the effectiveness of this Post-Effective Amendment to its Registration Statement pursuant to Rule 485(b)(1)(iii) under the Securities Act of 1933 and has duly caused this Post-Effective Amendment to its Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of New York and the State of New York, on July 29, 2026.

Pursuant to the requirements of the Securities Act of 1933, this Post-Effective Amendment to its Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.