B3, B03, B.III or B-3 may refer to:

Military

American bombers

  • Keystone B-3, a biplane bomber of the United States Army Air Corps
  • Next-Generation Bomber (2018 Bomber), next bomber follow-on to the B-2 stealth bomber program
  • Long Range Strike Bomber program, successor program to the 2018 Bomber program
  • Northrop Grumman B-21, a successor aircraft to the B-1 and B-52 bombers

German and Austro-Hungarian aircraft

  • AEG B.III, a German reconnaissance aircraft
  • Albatros B.III, a German Idflieg B-class designation aircraft
  • Aviatik B.III, a 1916 Austro-Hungarian reconnaissance aircraft
  • Euler B.III, a German Idflieg B-class designation aircraft
  • Fokker B.III (disambiguation), two aircraft models
  • Halberstadt B.III, a German Idflieg B-class designation aircraft
  • Kampfgeschwader 54, from its historic Geschwaderkennung code with the Luftwaffe in World War II
  • Lohner B.III
  • LVG B.III, a 1910s German two-seat trainer biplane

Submarines

  • USS B-3 (SS-12), a United States Navy submarine
  • HMS B3, a British B class submarine of the Royal Navy

Civilian transportation

Roads

  • B3 road (Kenya)
  • B3 road (Namibia)
  • Bundesstraße 3, a German national highway

Trains

  • Alsace-Lorraine B 3, an Alsace-Lorraine P 1<!--OK if first link red--> class steam locomotive
  • Bavarian B III, an 1852 German steam locomotive model
  • NCC Class B3, an 1890 Irish 4-4-0 passenger steam locomotive
  • NSB B3 (Class 3), Norwegian railway carriages
  • LNER Class B3, a British locomotive class

Other

  • B3 (New York City bus) serving Brooklyn
  • B3, a spur of the B (SEPTA Metro) in Philadelphia, PA, US
  • Bellview Airlines (International Air Transport Association code B3)

Biology and medicine

  • Vitamin B<sub>3</sub> (niacin)
  • B3 (classification), a medical-based Paralympic disability sport classification for blind sport
  • B3 domain, a highly conserved plant DNA-binding domain
  • Procyanidin B3, a plant phenolic compound
  • ATC code B03 Antianemic preparations, a subgroup of the Anatomical Therapeutic Chemical Classification System
  • Prodelphinidin B3, a plant phenolic compound

Computing

  • A TCSEC security class in the Trusted Computer System Evaluation Criteria
  • "B3 Coin" a cryptocurrency

Engines

  • A type of four-cylinder Mazda B engine
  • Benz B.III, an engine powering the 1914 Friedrichshafen FF.33<!--OK if first link red--> German aircraft

Music

  • B3 (band), an American boy band most popular in Germany
  • B3 (EP), a 2012 EP by alternative rock band Placebo
  • Hammond B-3, an electric organ

Other uses

  • B3 (stock exchange)
  • <math>B_3^I</math>, the Bochvar logic in calculus
  • B03, Alekhine's Defence chess code
  • B3: Battle by the Bay, a 1996 Street Fighter tournament
  • B3 oil field, an oil and gas field in the Baltic sea
  • Model B3 chair, a 1925 German Wassili designer chair
  • A subclass of B-class stars in stellar classification
  • a permission code for Town and country planning in the United Kingdom
  • Big Beautiful Bill, a 2025 omnibus bill proposed by POTUS Donald Trump
  • An ISO 216 international standard that defines paper size
  • B<sub>3</sub> the chemical formula for triboracyclopropenyl

See also

  • BE (disambiguation)
  • 3B (disambiguation)
  • BBB (disambiguation)