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 March 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 March 18, 2024, announcing the capital increase of the registrant's subsidiary, Kıbrıs Mobile Telekomünikasyon.

Istanbul, March 18, 2024

Announcement Regarding the Capital Increase in Kıbrıs Telekom

The capital of our Company's wholly-owned subsidiary Kıbrıs Mobile Telekomünikasyon Limited ("Kıbrıs Telekom") is increased by TRY 250,000,000 to TRY 322,724,863. Our Company's pre-emption rights with respect to the capital increase is fully paid.

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.