Onslaught may refer to:
- Onslaught (comics), a Marvel Comics supervillain
- Onslaught (Magic: The Gathering), an expansion to the Magic: The Gathering collectible card game
- Onslaught (video game), a 1989 Amiga beat'em up computer game
- Onslaught (2009 video game), a 2009 Wii first-person shooter video game
- Onslaught (band), a British thrash metal band
- Onslaught (novel), a 2002 science fiction novel by David Sherman and Dan Cragg
- Onslaught (Transformers) is the leader of the Combaticons, a Decepticon team in the Transformers series
- A gametype in the first-person shooter computer game Unreal Tournament 2004
- A co-op mode in the video game Battlefield: Bad Company 2
- Onslaught (Dove), a short film/advertisement made by Dove for their Campaign for Real Beauty