As filed with the Securities and Exchange Commission on May 21, 2021

Securities Act File No. 333-173276

Investment Company Act of 1940 File No. 811-22542

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT

UNDER

And

REGISTRATION STATEMENT

UNDER

SSGA Active Trust

(Exact Name of Registrant as Specified in Charter)

One Iron Street

Boston, Massachusetts 02210

(Address of Principal Executive Offices)

Registrant’s Telephone Number: (617) 664-1465

Sean O’Malley, Esq.

Senior Vice President and Deputy General Counsel

c/o SSGA Funds Management, Inc.

One Iron Street

Boston, Massachusetts 02210

(Name and Address of Agent for Service)

Copies to:

W. John McGuire, Esq.

Morgan, Lewis and Bockius LLP

1111 Pennsylvania Avenue, NW

Washington, DC 20004

It is proposed that this filing will become effective:

NOTE: This Post-Effective Amendment No. 171 to the Registrant’s Registration Statement on Form N-1A is being filed pursuant to paragraph (b)(1)(iii) of Rule 485 under the Securities Act of 1933, as amended (the “Securities Act”), solely for the purpose of delaying, until June 20, 2021, the effectiveness of Post-Effective Amendment No. 150 to the Registrant’s Registration Statement on Form N-1A related to the SPDR [SSGA Responsible Reserves ESG] ETF, which was filed pursuant to Rule 485(a) under the Securities Act on December 20, 2019 (the “Amendment”).

Part A. INFORMATION REQUIRED IN A PROSPECTUS

Part A is incorporated by reference to Part A of the Amendment.

Part B. INFORMATION REQUIRED IN A STATEMENT OF ADDITIONAL INFORMATION

Part B is incorporated by reference to Part B of the Amendment.

Part C. OTHER INFORMATION

Part C is incorporated by reference to Part C of the Amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, SSGA Active Trust, the Registrant, certifies that it meets all the requirements for effectiveness of this Registration Statement pursuant to Rule 485(b)(1)(iii) under the Securities Act of 1933, as amended, and has duly caused this Amendment to the Registration Statement to be signed on its behalf by the undersigned, thereunder duly authorized, in the City of Boston and the Commonwealth of Massachusetts on the 21^st day of May, 2021.

SIGNATURES

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: