DDX may refer to:
- , a common notation for the differential operator with respect to a variable x
- DD(X), former program name of a class of U.S. Navy destroyers
- Differential diagnosis (DDx or D/Dx), a systematic method used to identify unknowns
- Device Dependent X, graphics device drivers supporting 2D acceleration in the X.Org Server
- DDX (chemistry), a collective name for DDT and its breakdown products DDE and DDD
See also
edit- 3DDX, a rhythm video game
- DXD (disambiguation)