A21
A21 or A-21 stands for:
- a type of bus from the manufacturer MAN, see MAN Lion's City
- Aftokinitodromos 21 in Greece
Motorways and trunk roads:
- Motorway 21 (Belgium)
- Bundesautobahn 21 in Germany
- Autoroute A21 in France
- A21 road in Great Britain
- Autostrada A21 in Italy
- Vienna outer ring motorway in Austria
- Autoestrada A21 in Portugal
- Autovía A-21 in Spain
- Highway 21 (Switzerland)
- A21 (Kazakhstan)
