B2A

B2A may refer to:


 * Business-to-government (business-to-administration)
 * Haplogroup B2a, a subtype of Haplogroup B (mtDNA)
 * B2A (BRT), a bus route in Guangzhou
 * B2A class, traditional motorcycles with sidecars in sidecar racing for the Sidecar World Championship
 * Brantly B-2A light helicopter
 * Northrop-Grumman B-2A Spirit stealth bomber