As filed with the Securities and Exchange Commission on September 10, 2021

Securities Act File No. 33-26305

Investment Company Act File No. 811-05742

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	☒
Pre-Effective Amendment No.	☐
Post-Effective Amendment No. 1084	☒
and/or
REGISTRATION STATEMENT UNDER THE
INVESTMENT COMPANY ACT OF 1940	☒
Amendment No. 1086	☒
(Check appropriate box or boxes)

BLACKROCK FUNDS^SM

(Exact Name of Registrant as Specified in Charter)

100 Bellevue Parkway

Wilmington, Delaware 19809

United States of America

(Address of Principal Executive Office)

Registrant’s Telephone Number, including Area Code: (800) 441-7762

John M. Perlowski

BlackRock Funds^SM

55 East 52^nd Street

New York, New York 10055

United States of America

(Name and Address of Agent for Service)

Copies to:

Jesse C. Kean, Esq. Sidley Austin LLP 787 Seventh Avenue New York, New York 10019 Janey Ahn, Esq. BlackRock Advisors, LLC 55 East 52^nd Street New York, New York 10055

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

☐ Immediately upon filing pursuant to paragraph (b)

☒ On September 30, 2021 pursuant to paragraph (b)

☐ 60 days after filing pursuant to paragraph (a)(1)

☐ On (date) pursuant to paragraph (a)(1)

☐ 75 days after filing pursuant to paragraph (a)(2)

☐ On (date) pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

☒ This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

Title of Securities Being Registered: Shares of beneficial interest, par value $0.001 per share.

Explanatory Note

This Post-Effective Amendment No. 1084 under the Securities Act of 1933, as amended (the “Securities Act”) (Amendment No. 1086 under the Investment Company Act of 1940, as amended (the “1940 Act”)) to the registration statement on Form N-1A (the “Registration Statement”) of BlackRock Funds^SM (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 September 30, 2021, the effectiveness of the registration statement for BlackRock Infrastructure Sustainable Opportunities Fund, filed in Post-Effective Amendment No.  1075 on June 30, 2021, pursuant to paragraph (a) of Rule 485 under the Securities Act.

This Post-Effective Amendment No. 1084 incorporates by reference the information contained in Parts A, B and C of Post-Effective Amendment No. 1075 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 September 10, 2021.

BLACKROCK FUNDSSM (REGISTRANT) ON BEHALF OF
BLACKROCK INFRASTRUCTURE SUSTAINABLE OPPORTUNITIES FUND
By:	/S/ JOHN M. PERLOWSKI
(John M. Perlowski,
President and Chief Executive Officer)

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.

Signature	Title	Date
/S/ JOHN M. PERLOWSKI (John M. Perlowski)	Trustee, President and Chief Executive Officer (Principal Executive Officer)	September 10, 2021
/S/ TRENT WALKER (Trent Walker)	Chief Financial Officer (Principal Financial and Accounting Officer)	September 10, 2021
BRUCE R. BOND* (Bruce R. Bond)	Trustee
SUSAN J. CARTER* (Susan J. Carter)	Trustee
COLLETTE CHILTON* (Collette Chilton)	Trustee
NEIL A. COTTY* (Neil A. Cotty)	Trustee
LENA G. GOLDBERG* (Lena G. Goldberg)	Trustee
HENRY R. KEIZER* (Henry R. Keizer)	Trustee
CYNTHIA A. MONTGOMERY* (Cynthia A. Montgomery)	Trustee
DONALD C. OPATRNY* (Donald C. Opatrny)	Trustee

Signature	Title	Date
JOSEPH P. PLATT* (Joseph P. Platt)	Trustee
MARK STALNECKER* (Mark Stalnecker)	Trustee
KENNETH L. URISH* (Kenneth L. Urish)	Trustee
CLAIRE A. WALTON* (Claire A. Walton)	Trustee
ROBERT FAIRBAIRN* (Robert Fairbairn)	Trustee

*By:                /S/ JANEY AHN         (Janey Ahn, Attorney-In-Fact) September 10, 2021