The M14, officially referred to as the M14 Altunizade - Küçüksu metro line is a 7.3 km long rapid transit line project on the Anatolian side of Istanbul, with Altunizade as the first station and Küçüksu as the last station.

[2] When the project first came out, it was stated that the metro line would be built as a mini metro line between Kısıklı and Çamlıca Mosque, just like the M6 Levent - Boğaziçi University - Hisarüstü metro line.

After the Istanbul Metropolitan Municipality announced that this project was canceled, the Ministry of Transport and Infrastructure revised the project to be a standard metro line and undertook the construction of the project.

On 8 December 2023, Kâzım Karabekir station was canceled, 5 stations were added to the line and it was extended to Küçüksu.

[2] On 28 December 2023, Minister of Transport and Infrastructure Abdulkadir Uraloğlu announced that the first phase of the project between Altunizade and Bosna Bulvarı would be completed by the end of 2025.