M1 can mean the following:

• M1 Garand, a US battle rifle circa WWII.
• M1 Carbine, a US carbine circa WWII.
• M1 Abrams, a US Main Battle Tank.
• M1 freeway, Hungary a major superhighway in Hungary.
• M1 highway, Russia , a major highway in Russia.
• M1 motorway, a major highway in England, a major highway in Northern Ireland and a major highway in the Republic of Ireland
• Messier object M1, see Crab Nebula
• M1 in economics refers to the amount of cash in circulation plus the amount in checking or demand-deposit accounts. See money supply.
• M1 in neurology is the primary motor area of mammals.
• M1 Network a Russian television channel.
• M1 typewriter , the first product of Olivetti.