M Train or M-Train may refer to:

• M>Train, a former operator of half of Melbourne's suburban railway network and a former Melbourne tram service (2001–2004)
• M (New York City Subway service)
• MTR M-Train EMU or MTR Metro Cammell EMU, metro rolling stock of Hong Kong
• Train M, a former service of Helsinki commuter rail
• M Train (book), a 2015 book by Patti Smith
• The MTrain Tour, Meghan Trainor's second tour

• M-Bahn, a former Berlin magnetic levitation train (1989–1991)
• M line (disambiguation)
• M (disambiguation)