Form 8-A12B GMO ETF Trust

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-A

FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES

PURSUANT TO SECTION 12(b) or (g) OF

THE SECURITIES EXCHANGE ACT OF 1934

GMO ETF Trust

(Exact name of registrant as specified in its charter)

c/o Grantham, Mayo, Van Otterloo & Co. LLC

53 State Street

Boston, MA 02109

(Address of Principal Executive Offices, Zip Code)

Securities to be registered pursuant to Section 12(b) of the Act:

If this form relates to the registration of a class of securities pursuant to Section 12(b) of the Exchange Act and is effective pursuant to General Instruction A.(c), check the following box. ☒

If this form relates to the registration of a class of securities pursuant to Section 12(g) of the Exchange Act and is effective pursuant to General Instruction A.(d), check the following box. ☐

Securities Act registration statement file number to which this form relates:

333-274096

Securities to be registered pursuant to Section 12(g) of the Act:

None.

Item 1. Description of Registrant’s Securities to be Registered

A description of the shares of beneficial interest of GMO Power Infrastructure ETF, a series of the Registrant, is set forth in Post-Effective Amendment No. 11 to the Registrant’s Registration Statement on Form N-1A (the “Registration Statement”) (File Nos. 333- 274096; 811- 23895), as filed with the U.S. Securities and Exchange Commission (the “SEC”) via EDGAR Accession No. 0001193125-26-290588 on June 30, 2026, which description is incorporated herein by reference. Any amendment or form of supplement to the Registration Statement that is subsequently filed with the SEC that relates to the shares is hereby also incorporated herein by reference.

Item 2. Exhibits

SIGNATURE

Pursuant to the requirements of Section 12 of the Securities Exchange Act of 1934, the Registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereto duly authorized.