B20 may refer to:
Aircraft
- Blackburn B-20, a 1940 experimental aircraft
- Boeing Y1B-20, A Boeing experimental heavy bomber
- Douglas A-20 Havoc, designated the ZB-20 at the end of its life
Roads
- B20 motorway (Spain), a ring road around Barcelona in Catalonia
- B20 road (Cyprus)
<!-- * Bundesstraße 20, a German road -->
Other uses
- B20 (biodiesel), a mixture composed of 20% of biodiesel with 80% of diesel
- B20 (bronze), bell bronze or bell metal, a kind of bronze used in bells and cymbals
- B20 (New York City bus) serving Brooklyn
- Berezin B-20, a 20 mm caliber autocannon used by Soviet aircraft in World War II
- Honda B20 engine
- Volvo B20 engine
- 20 amp, type B – a standard circuit breaker current rating
- Bravo Two Zero, an eight-man British Special Air Service patrol that was tasked with finding Iraqi Scud missile launchers during the Gulf War
- The designation number assigned to the coupe version of the Lancia Aurelia motorcar, produced between 1951 and 1958
- Sicilian Defense, Encyclopaedia of Chess Openings code
- Boron-20 (B-20 or <sup>20</sup>B), an isotope of boron
- Burroughs B20, a line of microcomputers
- Business 20, an offshoot of the G20, which hopes to present a forum for the world's largest companies to discuss global issues
- B20 Summit, an international summit meeting of delegates from business groups around the world
See also
- B2O:
- Boron monoxide, a chemical compound with the symbol B<sub>2</sub>O
- b2o: an online journal, an American peer-reviewed online journal