Line M
- Boston
- List of rabbit breeds not recognized by the American Rabbit Breeders Association or the British Rabbit Council
- M (New York City Subway service)
- M Ocean View
- M line (disambiguation)
- Mattapan Line
- Meijō Line
- Midōsuji Line
- Minatomirai Line
- Nagoya
- New York City
- Osaka
- San Francisco
- Tokyo
- Tokyo Metro Marunouchi Line
- Yokohama