X3

X3 may refer to:__NOTOC__

Films, books, games and music

* "", also known as "X3" and "X-Men 3", the third film in the comic book film series
* "X3", a collection of three science fiction novellas by Gary A. Braunbeck
* "", a videogame prequel to X-Men: the Last Stand
* "", a space simulation computer game
* "", a sequel to "X³: Reunion"
* "Megaman X3", the third game in Capcom's Megaman X series; a platformer game
* "X3 (album)", a 2004 solo album by Japanese pop singer Aya Matsuura
* X3 (group), a Chicano rap group

Transportation and technology

* HMS "X3", an X class submarine of the Royal Navy
* Ilmor X3 "(also known as the X³)", a MotoGP race motorbike
* X-3 Stiletto, an experimental jet aircraft
* X-3 Jet Pack, a fictional rocket jet-pack from the movie Rocketeer
* X3 (train), a Swedish train
* BMW X3, the BMW Sports Activity Vehicle
* Korg X3, a synthesizer
* Foveon X3 sensor, a layered image sensor design
* XKO X3, a ERP software
* Xecuter 3, a fourth-generation Xbox modchip manufactured by TeamXecuter
* Hapag-Lloyd Express (IATA airline designator: X3), an airline doing business as TUIfly based in Hanover, Germany

Other

*X³, the mathematical cubic function
*X³, the mathematical notation representing a cube (algebra)
*X3, a subcommittee of ANSI
*X3 emoticon, indicate closed eyes "X" and cute (or cat) mouth "3", compared to ":3" or "XD"
*x3 internet slang, can be used for the verb love
*X3 is also an alternative term for the number 13 (for example, CorelDRAW X3 was released in 2006 as the 13th version of CorelDRAW)