Ratchet may refer to:
- Ratchet (device), a mechanical device that allows movement in only one direction
- Ratchet, a tool also known as a socket wrench
- Ratchet (instrument), a music instrument
In film and television:
- Ratchet (Transformers), a character in the franchise Transformers
- Ratchet (Robots), a character in the film Robots
- Ratchet, a character in the Widget the World Watcher television series
- Ratchet, a character in the Red Lantern Corps DC Comics series
In games:
- Ratchet (Ratchet & Clank), a game character
- Ratchet, a town in World of Warcraft
In other:
- Ratchet, a financial derivative also known as cliquet option