D3

Transportation

Roads

• London Buses route D3, a Transport for London contracted bus route
• D3 motorway (Czech Republic), a motorway in the Czech Republic
• D3 road (Croatia), a state road in Croatia
• D3 motorway (Slovakia), a motorway in northern Slovakia

Aircraft

• Albatros D.III, a 1916 German biplane fighter aircraft
• Dewoitine D.3, a Dewoitine aircraft
• Dunne D.3, a British Dunne aircraft
• Fokker D.III, a 1916 German single-seat fighter aircraft
• Mercedes D.III, a 1914 German 6-cylinder, liquid-cooled inline aircraft engine
• Phönix D.III, a variant of the Austro-Hungarian First World War Phönix D.I biplane fighter
• Pfalz D.III, a 1917 German fighter aircraft
• Schütte-Lanz D.III, a 1918 German fighter aircraft prototype
• Siemens-Schuckert D.III, a 1917 German prototype single-seat fighter aircraft

Automobiles

• Ford D3 platform, a full-size car automobile platform
• Peugeot D3, a panel van manufactured from 1950 to 1955

Locomotives

• Bavarian D III, an 1897 steam locomotive model
• LB&SCR D3 class, an 1893 British 0-4-4 tank locomotive design
• GS&WR Class D3, a Great Southern and Western Railway Irish steam locomotive
• GNR Class D3, which was also classified D3 during LNER ownership
• Pennsylvania Railroad class D3, an 1869 American steam locomotive model

Ships

• HMS Icarus (D03), a 1936 British Royal Navy destroyer
• HMS Ranee (D03), a 1943 British Royal Navy escort aircraft carrier
• USS D-3 (SS-19), a 1910 US Navy submarine
• D3-class motor torpedo boat, a Soviet motor torpedo boat class

Science and technology

• Dihedral group of order 6 (D**3)
• D-brane, a class of p-branes in theoretical physics
• D-3 (video), an uncompressed composite digital video tape format
• Nikon D3, a professional-level digital SLR camera
• Hexamethylcyclotrisiloxane, the threefold oligomer of dimethylsiloxane

Biology and medicine

• ATC code D03 Preparations for treatment of wounds and ulcers, a subgroup of the Anatomical Therapeutic Chemical Classification System
• Dopamine receptor D3, a human gene
• Vitamin D3 (cholecalciferol), a type of Vitamin D
• Melanoma in situ (ICD-10 code: D03)
• Iodothyronine deiodinase type III

Computing

• d3.js, Data Driven Documents, a JavaScript library for live web graphics based on changing data
• D3, a Pick database sold by Rocket Software
• DOCSIS 3, a cable modem standard

Entertainment

• D3 Digivice, a device from the fictional anime/manga Digimon series
• D3 (Tenchi Muyo! Ryo-Ohki), a character in the anime Tenchi Muyo!
• D3: The Mighty Ducks, the third film in The Mighty Ducks trilogy
• Dedication 3, a Lil' Wayne and Young Money mixtape
• Dhoom 3, a 2013 Indian Hindi-language action film by Vijay Krishna Acharya, third part of the Dhoom film series
• D3 (film), a 2023 Indian Tamil-language crime thriller by Balaaji

Video games

• Descent 3, a 1999 computer game
• Diablo III, a 2012 action role-playing game PC game by Blizzard Entertainment
• Dirt 3, a 2011 rallying video game
• Disciples III: Renaissance, a 2009 video game
• Disgaea 3, a 2008/2011 game in the Disgaea series
• Doom 3, a 2004 sci-fi horror first-person shooter computer game
• Driver 3, a 2004 racing, shooting, and adventure video game

Organizations

• D3 Publisher, a Japanese video game publisher
• Daallo Airlines, (IATA airline code), an airline based in Dubai

Other uses

• Dublin 3, a Dublin, Ireland postal district
• NCAA Division III, in American collegiate athletics
• USL League One, in American professional soccer, sometimes referred to as USL D3
• d3, a three-sided die in tabletop gaming
• d3, Mieses Opening in chess
• Voiced palato-alveolar affricate (former IPA symbol dʒ), a type of consonantal sound