Istanbul Metro

The 'M' logo, at the station entrance and passenger direction signs, should not be confused with the 'Metro Istanbul' logo for the company that operates the train system throughout Istanbul. The Istanbul Metro (Turkish: İstanbul metrosu) is a rapid transit railway network that serves the city of Istanbul, Turkey. Apart from the M11 line, which is operated by TCDD Taşımacılık, the system is operated by Metro Istanbul, a public enterprise controlled by the Istanbul Metropolitan Municipality. The oldest section of the metro is the M1 line, which opened on 3 September 1989. As of 2026, the system now includes 164 stations in service, with 32 more under construction. With 247.7 kilometers, Istanbul has the 23rd longest metro system in the world and the 4th longest in Europe as of 2026.

The system consists of eleven lines: the lines designated M1A, M1B, M2, M3, M6, M7, M9 and M11 are on the European side of the Bosporus, while lines M4, M5 and M8 are on the Asian side. Due to Istanbul's unique geography and the depth of the Bosporus strait which divides the city, the European and Asian metro networks do not connect directly. The two parts of the city are linked through the Marmaray commuter rail line, which is connected to the metro in several places. Four metro lines are under construction on the Asian side: M10 (Pendik Merkez–Fevzi Çakmak), M12 (60. Yıl Parkı–Kazım Karabekir), M13 (Emek–Yenidoğan) and M14 (Altunizade–Bosna Bulvarı). Additionally, extension works on the M1, M7 and M11 lines (on the European side) and the M4 line (on the Asian side) are underway.