Sheahan is a surname. Notable people with the surname include:
Bill Sheahan (umpire) (born 1953), Australian Test cricket match umpire
Bill Sheahan (politician) (1895–1975), Australian politician
Frank D. Sheahan (1901-1974), American politician
Frankie Sheahan (born 1976), rugby player
John Sheahan (born 1939), Irish violinist and folk musician
Maurie Sheahan (1905–1956), Australian rules footballer
Mike Sheahan (born 1945), Australian journalist
Paul Sheahan (born 1946), Australian Test cricketer
Riley Sheahan (born 1991), Canadian ice hockey player
Tom Sheahan (born 1968), Irish Fine Gael politician