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 (born 1941), Irish poet
 * Justin Grennan (born 1978), American singer
 * Keith Grennan (born 1984), American football player
 * Mike Grennan (1950–2009), American curler
 * Tom Grennan (born 1995), English singer and songwriter
 * Winston Grennan (1944–2000), Jamaican drummer
 * Jacqueline Grennan Wexler (1926–2012), American academic administrator