As filed with the Securities and Exchange Commission on July 26, 2018

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. 877	☒

and/or

REGISTRATION STATEMENT

UNDER

THE INVESTMENT COMPANY ACT OF 1940	☒
Amendment No. 879	☒

(Check appropriate box or boxes)

BLACKROCK FUNDS^SM

(Exact Name of Registrant as Specified in Charter)

100 Bellevue Parkway

Wilmington, Delaware 19809

(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:

John A. MacKinnon, Esq.	Benjamin Archibald, Esq.
Sidley Austin LLP	BlackRock Fund Advisors
787 Seventh Avenue	55 East 52nd Street
New York, New York 10019-6018	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 (date) 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.

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) 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 26, 2018.

BLACKROCK FUNDSSM (REGISTRANT)
	ON BEHALF OF ISHARES MUNICIPAL BOND INDEX 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	Trustee, President and Chief Executive	July 26, 2018
John M. Perlowski	Officer (Principal Executive Officer)
/s/ NEAL J. ANDREWS	Chief Financial Officer (Principal	July 26, 2018
Neal J. Andrews	Financial and Accounting Officer)
SUSAN J. CARTER*	Trustee
Susan J. Carter
COLLETTE CHILTON*	Trustee
Collette Chilton
NEIL A. COTTY*	Trustee
Neil A. Cotty
RODNEY D. JOHNSON*	Trustee
Rodney D. Johnson
CYNTHIA A. MONTGOMERY*	Trustee
Cynthia A. Montgomery
JOSEPH P. PLATT*	Trustee
Joseph P. Platt
ROBERT C. ROBB, JR.*	Trustee
Robert C. Robb, Jr.
MARK STALNECKER*	Trustee
Mark Stalnecker
KENNETH L. URISH*	Trustee
Kenneth L. Urish
CLAIRE A. WALTON*	Trustee
Claire A. Walton

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FREDERICK W. WINTER*		Trustee
Frederick W. Winter
ROBERT FAIRBAIRN*		Trustee
Robert Fairbairn
*By:	/s/ BENJAMIN ARCHIBALD		July 26, 2018
	(Benjamin Archibald, Attorney-in-Fact)

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EXHIBIT INDEX

Index No.	Description of Exhibit
EX-101.INS	XBRL Instance Document
EX-101.SCH	XBRL Taxonomy Extension Schema Document
EX-101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

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