X3
- 3X (disambiguation)
- Alstom
- Android One
- BMW X3
- Beijing X3
- Cowin X3
- Cygnus X-3
- Dance Dance Revolution X3
- Dongfeng Fengxing Jingyi X3
- Douglas X-3 Stiletto
- Eurocopter X3
- Foveon X3 sensor
- Gary A. Braunbeck
- Geely Vision X3
- Hapag-Lloyd Express
- Ilmor X3
- International Committee for Information Technology Standards
- Korg X3
- List of Metrobus routes (Washington, D.C.)
- Mega Man X3
- Nokia X3 Touch and Type
- Nokia X3-00
- Prospero (satellite)
- TUI fly Deutschland
- X-class submarine
- X3 (New York City bus)
- X3 (album)
- X3 (code)
- X3 (group)
- X3 (train)
- XKO X3