Sonic X may refer to:
- Sonic X - the anime adaptation of the Sonic franchise. Production by TMS Entertainment and originally broadcasted from 2003-2006 (2003-2004 in Japan).
- Sonic X (theme) - the intro theme of the TMS anime of the same name in the UK, NZ, and AUS versions of the show.
- Sonic X (comic series) - the comic adaptation of the TMS anime of the same name, produced by Archie Comics from 2005-2007.
- Sonic X (Leapster) - a Leapster game based on the anime series of the same name.
- Society for Observing and Neutralizing Inter-dimensional Creatures and Xenomorphs - an organization in the Sonic comics most commonly referred to as "S.O.N.I.C.X".