D2, an almond-shaped cloud on Neptune

D₂, Deuterium gas

R2-D2, Star wars robot

Diablo II, a computer game

D2 dopamine receptor

Driver 2, a videogame

d2, a brand of computer peripherals manufactured by the French firm électronique d2, now trading as LaCie

D2, the code for permission to use specific land or premises for leisure (cinemas, swimming baths, gymnasiums) in town and country planning in the UK,

Dotem, beings found in the anime series RahXephon

D2 (video game), a video game for the Sega Dreamcast

Dublin 2, a postcode

d2, role-playing game dice notation for a two-sided die, such as a coin.

D2 (video format), a professional digital video format

Marcelo D2, a Brazilian rapper.

Vitamin D2, Ergocalciferol

Datasaab D2, a concept computer designed by the Swedish firm Datasaab

D2 kit, a microprocessor development kit MEK6800D2

Highway D2, in the Czech Republic

Highway D2, in Slovakia

D2 (D2 Mannesmann), former name of Vodafone's German division, which resulted from the acquisition of the German company Mannesmann AG