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.
• 8-in Howitzer M1, a US artillery piece circa WWII.
• Several roads:
  • M1 freeway, Hungary a major superhighway in Hungary.
  • M1 highway, Russia , a major highway in Russia.
  • M1 motorway, a major motorway in England.
  • M1 motorway, a major motorway in Northern Ireland.
  • M1 motorway, a major motorway 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.
• HMS M1, an early Royal Navy submarine
• M1 typewriter , the first product of Olivetti.
• M1 class steam locomotive of the Pennsylvania Railroad.
• The Korg M1 keyboard synthesizer.
• M1 is an abbreviation of MobileOne, a telecommunications company in Singapore.