B57

B57 or B-57 may refer to:
 * BMW B57, a turbo-diesel straight-six engine, produced by BMW since 2015
 * Bundesstraße 57, a German road
 * B57 (New York City bus) in Brooklyn
 * B57 nuclear bomb
 * B-57 Canberra, a US-built version of the English Electric Canberra bomber
 * Volvo B57, a bus
 * Sicilian Defence in the Encyclopaedia of Chess Openings
 * HLA-B57, an HLA-B serotype