UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of May 2026

Commission File Number: 001-42767

J-Star Holding Co., Ltd.

(Registrant’s Name)

7/F-1, No. 633, Sec. 2, Taiwan Blvd.,

Xitun District, Taichung City 407,

Taiwan (R.O.C.)

(Address of Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F ☒

Form 40-F ☐

INFORMATION CONTAINED IN THIS FORM 6-K REPORT

On May 26, 2026, J-Star Holding Co., Ltd. (the “Company”) issued a press release announcing “J-Star Holding Subsidiary Receives Central Bank of Taiwan Authorization to initiate $60 Million Sovereign-Backed Financing Framework through designated banks for proposed U.S. Solid-State Battery Expansion ($122.5 Million Project)”. This press release is furnished herewith as Exhibit 99.1.

Exhibits.

The following exhibits are being filed herewith:

Exhibit No.		Description
99.1		Press Release, dated May 26, 2026.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	J-Star Holding Co., Ltd.

	By:	/s/ Jing-Bin Chiang
	Name:	Jing-Bin Chiang
	Title:	Chief Executive Officer

Date: May 26, 2026

J-Star Holding Co., Ltd. 6-K