Muck can refer to:
- Muck (soil), a dirt and water
- Muck, Scotland, an island in Scotland
- Muck (gambling), a number of actions (both legal and illegal)
- Muck (mining), sorting out the rich ore from the poor rock in an underground metallic mine after blasting
- A "Multi-User Chat Kingdom" (see MUD)
- Something scandalous. A journalist who publishes scandalous things is called a muckraker.
- Jeff Bezos, CEO of Amazon.com, has used the term "Muck" to describe his firm's rentable utility-computing infrastructure.
