Grennan
Grennan is an Irish surname. It may be of Norman origin, from the French name Grenan. Notable people with the surname include:
- Eamon Grennan, Irish poet
- James Grennan, Irish Gaelic footballer who played for Offaly
- Justin Grennan, American singer
- Keith Grennan, American football player
- Mike Grennan, American curler
- Seán Grennan, Irish dual player of Gaelic football and hurling who played for Offaly
- Tom Grennan, English singer and songwriter
- Winston Grennan, Jamaican drummer
- Jacqueline Grennan Wexler, American academic administrator