M1M1 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
- 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.