Hannon is a surname, and may refer to
- Brian Hannon, Northern Irish clergyman
- Dinny Hannon, Irish Footballer
- Ezra Hannon, pseudonym used by Evan Hunter
- James Hannon, Bronx Irish-American filmmaker
- Kemp Hannon, member of the New York State Senate
- Mary Josephine Hannon, the grandmother of President John F. Kennedy
- Neil Hannon, Northern Irish singer of The Divine Comedy, son of Brian Hannon
- Patrick Hannon, British politician
- Richard Hannon, British horse trainer
- William Hannon, former president of St. Ambrose University
Hannon may also refer to:
- Point Hannon, a sand spit in Hood Canal
- Patrick Hannon (Hannan) discovered the Kalgoorlie Goldfield in Australia