Onslaught may refer to:
Characters
- Onslaught (Marvel Comics), a Marvel Comics supervillain
- Onslaught (DC Comics), a DC Comics team of Quraci terrorists
- Onslaught (Transformers), the leader of the Combaticons in the Transformers series
Games
- Onslaught (Magic: The Gathering), an expansion to the Magic: The Gathering collectible card game
- Onslaught, a gametype in the first-person shooter computer game Unreal Tournament 2004
- Onslaught (1989 video game), a 1989 Amiga beat'em up computer game
- Onslaught (2009 video game), a 2009 Wii first-person shooter video game
- A co-op mode in the video game Battlefield: Bad Company 2
- ONSlaught, a libre game engine cloning the proprietary engine NScripter.
- Mortal Kombat: Onslaught a 2023 RPG by NetherRealm Studios.
Other
- Onslaught, an upcoming action horror film
- Onslaught (band), a British thrash metal band
- Onslaught (novel), a 2002 science fiction novel by David Sherman and Dan Cragg
- Onslaught (Dove), a short film/advertisement made by Dove for their Campaign for Real Beauty