Conn may refer to:
- Conn (name), a family name and a masculine given name
- Conn, mythological son of Ler from the Children of Lir legend
- Conn of the Hundred Battles, a figure from Irish mythology
- Jerome W. Conn, American endocrinologist
- Connecticut, State in the northeastern United States
- Connecticut College, a liberal arts college in New London, Connecticut, USA
- Conn, Mississippi, United States
- Conn, Ontario, Canada
- Conn (nautical), the duty of giving directions for movement from the deck of a ship to the helm
- C.G. Conn, Inc., a manufacturer of musical instruments
- CONN (functional connectivity toolbox), a cross-platform imaging software program