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 September 2026

Commission File Number: 001-41927

SU Group Holdings Limited

(Registrant’s Name)

7^th Floor, The Rays
No. 71 Hung To Road, Kwun Tong
Kowloon, Hong Kong

(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

Explanatory Note

Exhibit 99.1 included with this Report on Form 6-K is hereby incorporated by reference into the Company’s Registration Statement on Form F-3 (Reg. No. 333-282687), including the prospectuses contained therein and shall be deemed to be a part thereof from the date on which this Report on Form 6-K is furnished, to the extent not superseded by documents or reports subsequently filed or furnished.

EXHIBIT INDEX

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.