Line M
Line M may refer to:
- M (New York City Subway service), a rapid transit service in New York City
- Mattapan Line, a light rail line in Boston
- Tokyo Metro Marunouchi Line, a rapid transit line in Tokyo
- M Ocean View, a light rail line in San Francisco
- Midōsuji Line, a rapid transit line in Osaka
- Minatomirai Line, a rapid transit line in Yokohama
- Meijō Line, a rapid transit line in Nagoya
- Moshtohor, a rabbit breed