D2
D2, D02, D.II, D II or D-2 may refer to:

Places
Dublin 2, a Dublin, Ireland postcode
D2 motorway (Czech Republic)
D2 road (Croatia), a state route in Croatia
D2 motorway (Slovakia)
Mount Dulang-dulang, the second highest mountain of the Philippines
D2, a line of Moscow Central Diameters

Arts & entertainment
D-2 (mixtape), a 2020 album by South Korean rapper Agust D
D2: The Mighty Ducks, the second film in The Mighty Ducks trilogy
R2-D2, a robotic Star Wars character
"D²", a 2002 episode of Dexter's Laboratory
D2 (video game), a 1999 game for the Sega Dreamcast
D2, an abbreviation of the video game Diablo II or Destiny 2

Business
D2 (hotel chain), owned by Dusit Thani Group
D2 Mannesmann, the former name of Vodafone's German division, which resulted from the acquisition of the German company Mannesmann AG
D2 (magazine), published by Dagens Næringsliv
D2, the IATA code for Damania Airways

Biology or medicine
ATC code D02 Emollients and protectives, a subgroup of the Anatomical Therapeutic Chemical Classification System
Dopamine receptor D2, a protein
Levuglandin D2
Prostaglandin D2 receptor, a G-protein coupled receptor
Resolvin D2
Cyclin D2 (CCND2)
Vitamin D2, or ergocalciferol
D02, the ICD-10 code for carcinoma in situ of middle ear and respiratory system
DIO2, Type II iodothyronine deiodinase, an enzyme involved in the thyroid system

Vehicles
Aircraft
Albatros D.II, a 1916 German fighter aircraft
Aviatik (Berg) D.II, a 1917 -Hungarian fighter prototype
STS-55 or D2, the second German-sponsored Spacelab mission
Daimler D.II, a Daimler aircraft
Delta D2, an Australian diesel-powered helicopter design
Dunne D.2, a British Dunne aircraft
Euler D.II, a 1917 German single-seat fighter
Fokker D.II, a WWI German fighter biplane
Halberstadt D.II, a 1916 German biplane fighter aircraft
Hughes D-2, a 1943 mysterious American fighter and bomber project
LFG Roland D.II, a 1917 German single-seat fighter
Phönix D.II, a variant of the Hungarian First World War biplane fighter  D.I
Schütte-Lanz D.II, a 1915 variant of the German Schütte-Lanz D.I aircraft

Aircraft engines
Alfa Romeo D2, a 1931 Italian nine-cylinder radial engine for aircraft use
Mercedes D.II, a WWI 6-cylinder, liquid-cooled inline aircraft engine

Locomotives
Bavarian D II, an 1898 German goods train tank locomotive model
Bavarian D II (Ostbahn), an 1866 German goods train tender locomotive model
Bavarian D II (old), an 1873 small tank locomotive
GS&WR Class D2, a Great Southern and Western Railway Irish steam locomotive
LB&SCR D2 class, a British locomotive class
GNR Class D2, a class of British steam locomotives
PRR D2, an 1868 American steam locomotive model

Ships
HMS Attacker (D02), a 1941 American-built escort aircraft carrier
HMS Devonshire (D02), a 1962 County-class destroyer
HMS Inglefield (D02), a 1936 I-class destroyer and flotilla leader of the British Royal Navy
USS D-2 (SS-18), a 1909 American submarine

Other vehicles
Char D2, a French tank

Electronics
Cowon D2, a 2007 portable media player with touch screen interface
Datasaab D2, a Swedish concept computer completed in 1960
d2, a brand of computer peripherals manufactured by the French firm électronique d2, now trading as LaCie
D2 kit, a microprocessor development kit MEK6800D2
D-2 (video), a professional digital video format
DOCSIS 2, a cable modem standard

Other uses
D2, the Codex Claromontanus, a 6th-century Greek-Latin uncial manuscript of the New Testament
D2, a dihedral group in group theory
D2, deuterium, an isotope of hydrogen
D2, an almond-shaped cloud on Neptune
D2, the code for permission to use specific land or premises for leisure (cinemas, swimming baths, gymnasiums) in town and country planning in the United Kingdom
Division II (disambiguation), in sports leagues, etc.
Marcelo D2 (born 1967), Brazilian rapper
D2, an abbreviation for DOCSIS 2.0, an international telecommunications standard
D2 steel, a type of D-Grade tool steel with good wear resistance commonly found in shears and high end knives
D2, gaming notation for a 2-sided die, such as a coin
D2, a standard paper size between B2 and A1
D2 Subway, a planned Dallas, Texas light rail tunnel

See also
2D (disambiguation)
DII (disambiguation)