KOI may refer to:
- KOI character encodings, for Cyrillic script
- Indonesian Olympic Committee ()
- Kepler object of interest
- Kirkwall Airport (IATA airport code)
- Komi-Permyak language (ISO language code)
- Movistar KOI (Spanish professional esports organization)
- Torre KOI (skyscraper in Mexico)
- Toronto KOI (Canadian professional esports organization)
See also
- KOI-18, a cryptographic fill device used by the U.S. government
- Koi (disambiguation)