M21
M21 or M 21 stands for:
- an open star cluster in the constellation Sagittarius, see Messier 21
- the sniper rifle M21 (rifle)
- the Moldovan trunk road Drum public național M21
- the former Russian trunk road M21 (Russia)
- the Ukrainian trunk road M 21 (Ukraine)
- a six-cylinder diesel engine from Bayerische Motoren Werke, see BMW M21
- a school biplane made by Messerschmitt Flugzeugwerke, see Messerschmitt M21
- Autópálya M21 (Hungary)
- Multicar M21 , motor vehicle
M-21 stands for:
- Lockheed M-21 , American carrier aircraft
