Otta may refer to:
- A preliminary name of the yotta SI unit prefix.
- In Norse mythology, Hildisvini, also known as "Otta the Simple", who was Freya's lover.
- Otta, Norway, a Norwegian town in Gudbrandsdal.
- The Otta River in Norway.
- An alternative spelling of Ota, Nigeria, a city in Ogun State, Nigeria
- Otta (weapon), a curved stick used in the Indian martial art of Kalarippayattu.
- On the Turning Away, a song by Pink Floyd.