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
 * D2 Place One and Two, at Cheung Yue Street and Cheung Shun Street,in Cheung Sha Wan,MTR Lai Chi Kok Station Exit D1 and D2.

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
 * Dhoom 2, a 2006 Indian Hindi-language action film by Sanjay Gadhvi, second part of the Dhoom film series

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

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
 * Zhidou D2, a Chinese small electric car

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
 * D2, the Double Dragon hacking group
 * 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