The Istanbul Metro 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 in 1989. As of March 2024, the system now includes 158 stations in service, with 36 more under construction. Istanbul is the city with the 22nd longest metro line in the world and the 4th in Europe.

The M2, officially referred to as the M2 Yenikapı–Hacıosman metro line, is a rapid transit line of the Istanbul Metro. It is colored light green on the maps and route signs. The M2 operates between Hacıosman in southern Sarıyer to Yenikapı in south-central Fatih on the historic peninsula of Istanbul. Shuttle trains run from Sanayi to Seyrantepe to Rams Park. The M2 line has 16 stations, all but one underground, and a total length of 23.49 kilometers (14.60 mi). A daily ridership of about 500,000 makes it the busiest line of the Istanbul Metro system.