6-K - ioneer Ltd (0001896084) (Filer)

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 of the

Securities Exchange Act of 1934

For the month of October 2026

Commission File Number: 001-41412

ioneer Ltd

(Translation of registrant’s name into English)

Suite 16.01, 213 Miller Street

North Sydney, NSW, 2060, Australia

(Address of principal executive offices)

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

Form 20-F ☒    Form 40-F ☐

EXHIBIT INDEX

The following exhibits are filed as part of this Form 6-K:

SIGNATURE

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.