Tokyo Metro Marunouchi Line (東京地下鉄丸ノ内線) is a subway line, part of the Tokyo Metro system in Tokyo, Japan. It is the second line to be built in the city, and the first one constructed after 1945. The route is U-shaped, running from Ogikubo Station in the west of the city via the commercial and administrative district of Shinjuku through to the Marunouchi commercial center around Tokyo Station, before turning back and heading to Ikebukuro. The Marunouchi Line's color on maps is red. Its stations carry the letter M followed by a number. A branch line goes to Honancho; its stations have a lowercase m.

Stations (Transfers)

• M-25 Ikebukuro Station (Yurakucho, Yamanote, Saikyo, Utsunomiya, Takasaki, Shonan Shinjuku lines)
• M-24 Shin-Otsuka Station
• M-23 Myogadani Station
• M-22 Korakuen Station (Namboku, Mita, Oedo Lines (Kasuga Station))
• M-21 Hongo Sanchome Station (Oedo; no transfer)
• M-20 Ochanomizu Station (Chuo, Sobu Main Lines)
• M-19 Awajicho Station (Chiyoda (Shin-Ochanomizu Station), Shinjuku (Ogawa-machi) Lines)
• M-18 Otemachi Station (Tozai, Chiyoda, Hanzomon, Mita Lines)
• M-17 Tokyo Station
• M-16 Ginza Station (Ginza, Hibiya Lines)
• M-15 Kasumigaseki Station (Hibiya, Chiyoda Lines)
• M-14 Kokkai Gijido-Mae Station
• M-13 Akasaka Mitsuke Station (Ginza, Yurakucho, Hanzomon, Namboku (Nagata Station) Lines)
• M-12 Yotsuya Station (Namboku, Chuo Lines)
• M-11 Yotsuya Sanchome Station
• M-10 Shinjuku Gyoen-mae Station
• M-9 Shinjuku Sanchome Station (Shinjuku Line)
• M-8 Shinjuku Station
• M-7 Nishi Shinjuku Station
• M-6 Nakano Sakaue Station (Oedo Line)
• M-5 Shin Nakano Station
• M-4 Higashi Koenji Station
• M-3 Shin Koenji Station
• M-2 Minami Asagaya Station
• M-1 Ogikubo Station (Chuo Main Line)

Honancho branch line: