The Moscow Metro (Russian: Моско́вский метрополите́н, tr. Moskovsky metropoliten, IPA: [mɐˈskofskʲɪj mʲɪtrəpəlʲɪˈtɛn]) is a rapid transit system serving Moscow, Russia and the neighbouring Moscow Oblast cities of Krasnogorsk, Reutov, Lyubertsy and Kotelniki. Opened in 1935 with one 11-kilometre (6.8 mi) line and 13 stations, it was the first underground railway system in the Soviet Union. As of 2017, the Moscow Metro excluding the Moscow Central Circle and Moscow Monorail has 206 stations and its route length is 339.1 km (210.7 mi), making it the fifth longest in the world. The system is mostly underground, with the deepest section 84 metres (276 ft) underground at the Park Pobedy station, one of the world's deepest.
The Moscow Metro, a state-owned enterprise, is 339.1 km (210.7 mi) long and consists of twelve lines and 203 stations organized in a spoke-hub distribution paradigm, with the majority of rail lines running radially from the centre of Moscow to the outlying areas. The Koltsevaya Line (route 5) forms a 20-kilometre (12 mi) long ring which enables passenger travel between these spokes, and the Moscow Railway-operated Moscow Central Circle (route 14) forms a 54-kilometre (34 mi) long ring that serves a similar purpose. Most stations and lines are underground, but some lines have at-grade and elevated sections; the Filyovskaya Line, Butovskaya Line and the Central Circle Line are the three lines that are at grade or mostly at grade.
The Moscow Metro uses the Russian gauge of 1,520 millimetres (60 in), like other Russian railways, and an underrunning third rail with a supply of 825 V DC. The average distance between stations is 1.7 kilometres (1.1 mi); the shortest (502 metres (1,647 ft) long) section is between Vystavochnaya and Mezhdunarodnaya and the longest (6.627 kilometres (4.118 mi) long) is between Krylatskoye and Strogino. Long distances between stations have the positive effect of a high cruising speed of 41.7 kilometres per hour (25.9 mph).
Moscow Metro starts opening at 05:25 and closes at 01:00. The precise opening time varies at different stations according to the arrival of the first train, but all stations simultaneously close their entrances at 01:00 am for maintenance, and so do transfer corridors. The minimum interval between trains is 90 seconds during the morning and evening rush hours.
As of 2013 the system has an average daily ridership of 6.73 million passengers with the peak of 9.28 million.
Since 1 December 2014 free Wi-Fi was available on all lines of the Moscow Metro. The network was launched by MaximaTelecom.