AS FILED WITH THE U.S. SECURITIES AND EXCHANGE COMMISSION ON APRIL 28, 2025

1933 Registration File No. 333-221764

1940 Act File No. 811-23312

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

TIDAL TRUST III

(Exact Name of Registrant as Specified in Charter)

c/o Tidal ETF Services LLC

234 West Florida Street, Suite 203

Milwaukee, Wisconsin 53204

(Address of Principal Executive Offices, Zip Code)

(Registrant’s Telephone Number, including Area Code) (855) 843-2534

The Corporation Trust Company

1209 Orange Street

Corporation Trust Center

Wilmington, DE 19801

(Name and Address of Agent for Service)

Copies to:

Approximate date of proposed public offering: As soon as practicable after the effective date of this registration statement.

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

If appropriate, check the following box:

EXPLANATORY NOTE

Designation of New Effective Date for Previously Filed Amendment

Post-Effective Amendment No. 104 (the “Amendment”) was filed pursuant to Rule 485(a)(1) under the Securities Act of 1933 on February 28, 2025, and pursuant to Rule 485(a)(1) would have become effective on April 29, 2025.

This Post-Effective Amendment No. 111 is being filed pursuant to Rule 485(b)(1)(iii) for the sole purpose of designating May 22, 2025, as the new date upon which the Amendment shall become effective.

This Post-Effective Amendment No. 111 incorporates by reference the information contained in Parts A, B, and C of the Amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, (the “Securities Act”) and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all of the requirements for effectiveness of this Post-Effective Amendment No. 111 to its Registration Statement on Form N-1A under Rule 485(b) under the Securities Act and has duly caused this Post-Effective Amendment No. 111 to its Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of Milwaukee, State of Wisconsin, on April 28, 2025.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed below by the following persons in the capacities indicated on April 28, 2025.