B21 (disambiguation)

B21 may refer to:

* B21, a bhangra group
* B-21 (machine), a cypher machine (see Boris Hagelin)
* B21 (New York City bus) serving Brooklyn
* HLA-B21, an HLA - B serotypeand also :
* North American XB-21, an experimental bomber aircraft
* Volvo Redblock Engine, an automotive engine
* Bundesstraße 21, a German road