B2, B02, B.II, B.2 or B-2 may refer to:

Transportation

AEG B.II, a German aircraft during World War I
Albatros B.II, a 1914 unarmed German two-seat reconnaissance biplane
Aviatik B.II, a 1915 German reconnaissance aircraft
Blackburn B-2, a British biplane side-by-side trainer aircraft
Brantly B-2, a helicopter
Curtiss B-2 Condor, an American biplane bomber built before World War II
DFW B.II, a 1914 German aircraft
Euler B.II, a German Idflieg B-class designation aircraft
Farman B.2, a French Farman aircraft
Flanders B.2, a 1912 British experimental biplane
Fokker B.II (1916), two different German unarmed observation aircraft of World War I
Fokker B.II (1923), a 1923 Dutch reconnaissance flying boat
Halberstadt B.II, a German Idflieg B-class designation aircraft
Lohner B.II
LVG B.II, a 1910s German two-seat reconnaissance biplane
Northrop Grumman B-2 Spirit, an American stealth bomber of the United States Air Force
Avro Vulcan B2, the Mark 2 version of a Royal Air Force V-Bomber aircraft
Any Mark 2 bomber aircraft under the British military aircraft designation systems

Alsace-Lorraine B 2, an Alsace-Lorraine P 1 class steam locomotive
Bavarian B II, an 1851 German steam locomotive model
GS&WR Class B2, a Great Southern and Western Railway Irish steam locomotive
LB&SCR B2 class, a British LB&SCR locomotive class
GCR Class 1, classified B2 during ownership, reclassified B19 in 1945
LNER Thompson Class B2, a British class of 4-6-0 steam locomotives rebuilt from B17s
NCC Class B2, a Northern Counties Committee Irish steam locomotive

B2 (New York City bus) serving Brooklyn
Belavia Belarusian Airlines (IATA airline designator code B2)
Marussia B2, a high-performance luxury sports coupé built by Russian automaker Marussia Motors
Guangzhou Metro CSR-Zhuzhou Class B EMU, internal callsign B2 for the first batch

Computing

b2/cafelog, the precursor to the WordPress blogging software
B2evolution, a multi-lingual, multi-user, multi-blog publishing system forked from b2/cafelog
B2, a subclass of security level B as defined by Trusted Computer System Evaluation Criteria (TCSEC) standards
B2, a cloud-based object storage service provided by Backblaze

B2, the name of a character from the Dutch television series Bassie en Adriaan
B-2 or B² (B squared), the stage name used by wrestler Barry Buchanan
B2, one of a pair of bananas featured in the children's television show Bananas in Pyjamas
Birch Bayh (Birch Evans Bayh II)

South Korea B-2 visa, a tourist or transit visa granted by South Korea
United States B-2 visa, a non-immigrant visa granted by the United States of America

ATC code B02 Antihemorrhagics, a subgroup of the Anatomical Therapeutic Chemical Classification System
Bradykinin receptor B₂, a human gene
Proanthocyanidin B2, a B type proanthocyanidin
Thromboxane B2, an inactive metabolite/product of thromboxane A2
Vitamin B₂

B2, a postcode area in central Birmingham
B2 basketball league (Albania); see Albanian Basketball League
B2, an international standard paper size defined in ISO 216 measuring 500 mm × 707 mm
B2, a level in the Common European Framework of Reference for Languages
B2, a code used by the land use planning system in the UK
B2 star, a subclass of bluish-white B-class stars
B02, Alekhine's Defence chess code
B2 dye, also known as dyesol
B2 (classification), a Paralympic disability classification
Bi-2, a Russian rock band
B2 intermetallic compound with equal numbers of atoms of two metals
B2, an advanced model of battle droid in the Star Wars franchise
B2, a brand of Canadian retailer Browns Shoes