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 April 2024

Commission File Number: 001-15092

TURKCELL ILETISIM HIZMETLERI A.S.

(Translation of registrant’s name into English)

Aydınevler Mahallesi İnönü Caddesi No:20

Küçükyalı Ofispark

34854 Maltepe
Istanbul, Turkey

(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:

x Form 20-F  ¨ Form 40-F

Enclosure: A press release dated April 24, 2024, announcing the Ukrainian Court decision to lift the order for seizure of the shares of the registrant’s companies, lifecell LLC, UkrTower LLC, and Paycell LLC.

Istanbul, April 24, 2024

Announcement Regarding Ukrainian Court Decision

As per our announcement dated March 8, 2024, our subsidiary has been notified that the Ukrainian courts have lifted the order for the seizure of the shares of our companies, lifecell LLC, UkrTower LLC, and Paycell LLC.

The process of fulfilling the closing prerequisites is ongoing in the transfer of all shares of our subsidiaries in Ukraine to NJJ Capital.

For more information:

Turkcell Investor Relations

investor.relations@turkcell.com.tr

Tel: + 90 212 313 1888

SIGNATURES

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