As filed with the U.S. Securities and Exchange Commission on June 30, 2026

File No.  333-191495

File No.  811-22895

U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

Capitol Series Trust

(Exact Name of Registrant as Specified in Charter)

225 Pictoria Drive, Suite 450, Cincinnati, Ohio 45246

 (Address of Principal Executive Offices, Zip Code)

513-587-3400

(Registrant’s Telephone Number, including Area Code)

Matthew J. Miller

President and Chief Executive Officer

Capitol Series Trust

225 Pictoria Drive, Suite 450, Cincinnati, Ohio 45246

 (Name and Address of Agent for Service)

Copy to:

Thomas G. Sheehan

Practus LLP

11300 Tomahawk Creek Pkwy

Suite 310

Leawood, KS 66211

It is proposed that this filing will become effective:

If appropriate, check the following box:

EXPLANATORY COMMENT

This Post-Effective Amendment to the Registration Statement of Capitol Series Trust (the “Registrant”) on Form N-1A on behalf of the MRP SynthEquity® Nasdaq 100 ETF is being filed for the purpose of designating a new effective date for the previously filed Post-Effective Amendment No. 178 to the Registrant’s Registration Statement filed under Rule 485(a) of the Securities Act of 1933, as amended, which was filed for the purpose of adding the MRP SynthEquity® Nasdaq 100 ETF as a new series. This Post-Effective Amendment No. 184 to the Registration Statement of the Registrant incorporates by reference Parts A, B and C contained in Post-Effective Amendment No. 178 to the Registration Statement of the Registrant filed with the U.S. Securities and Exchange Commission on April 17, 2026.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, (File No. 333-191495) and the Investment Company Act of 1940 (File No. 811-22895), the Registrant, Capitol Series Trust, has duly caused this Post-Effective Amendment No. 184 to the Registration Statement to be signed on its behalf by the undersigned, thereto duly authorized, in the City of Cincinnati and State of Ohio, on the 30^th day of June, 2026.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Post-Effective Amendment No. 184 to the Registration Statement has been signed below by the following persons in the capacities and on the 30^th day of June, 2026: