M21

The abbreviation M21 or M 21 indicates, among other

• An open cluster in the constellation Sagittarius, see Messier 21
• The sniper rifle M21 ( rifle)
• Russian M21 highway (Russia)
• A six-cylinder diesel engine from BMW
• A double-decker school of the Messerschmitt aircraft factory, see Messerschmitt M21
• Autópálya M21 (Hungary )
• Multicar M21, motor vehicle

• Disambiguation
• Abbreviation