B3

B3, B03, B.III or B-3 may refer to:
* B3 (boy band), an American boy band most well-known in Germany
* B3 domain, a highly conserved plant DNA-binding domain
* B3 Henk, a Dutch artist who makes several different styles of music
* B-3 Long Range Strike Platform, a successor aircraft to the B-1, B-2, and B-52
* B3 (New York City bus) serving Brooklyn
* B3 oil field, an oil and gas field in the Baltic sea
* B3 road (Cyprus)
* AEG B.III, a German reconnaissance aircraft
* Albatros B.III, a German aircraft
* Alsace-Lorraine B 3, a Alsace-Lorraine P 1 class steam locomotive
* ATC code B03, a section of the Anatomical Therapeutic Chemical Classification System
* Aviatik B.III, a 1916 Austro-Hungarian reconnaissance aircraft
* Bavarian B III, a 1852 German steam locomotive model
* Bensen B-3, a
* Benz B.III, an engine powering the 1914 Friedrichshafen FF.33 German aircraft
* Euler B.III, a German aircraft
* Fokker B.III, two aircraft model
* Halberstadt B.III, a German aircraft
* Hammond B-3, an electric organ made by Hammond
* Keystone B-3, a United States Air Force aircraft
* Lohner B.III
* LVG B.III, a 1910s German two-seat trainer biplane
* Model B3 chair, a 1925 German Wassili designer chair
* NCC Class B3, a 1890 Irish 4-4-0 passenger steam locomotive
* USS "B-3" (SS-12), a United States Navy submarine
* HMS "B3", a British B class submarine of the Royal Navy
* PRR B3, an American electric model
* Vitamin B3

and also :
* Bundesstraße 3, a German national highway
* an ISO 216 international standard that defines paper size
* a type of four cylinder Mazda B engine
* the International Air Transport Association code for Bellview Airlines
* a subclass of B-class stars in stellar classification
* a permission code for Town and country planning in the United Kingdom
* a TCSEC security class in the Trusted Computer System Evaluation Criteria
* Big Brother Bot, a game administration bot for Call of Duty and Call of Duty 2
* B03, Alekhine's Defence chess code