Dillon was born in New Rochelle, New York, the son of Mary Ellen, a homemaker, and Paul Dillon, a portrait painter, sales manager, and golf coach at Fordham University. He is the younger brother of actor Matt Dillon. Both brothers attended Mamaroneck High School. His paternal grandmother was the sister of comic strip artist Alex Raymond, the creator of Flash Gordon.\n', '
Dillon began acting in both television and films in the 1980s and first received wide attention for his role as the psychopathic soldier Bunny in the 1986 film Platoon. In 1983, Dillon played Arnold Norberry in the TV Movie No Big Deal. In 1988, he portrayed Brian Flagg in a remake of the 1958 American science fiction film The Blob. The remake flopped, earning only 8.2 million against a budget of 19 million, although in recent years it has gained a devoted cult following. Other notable film roles from that period included War Party (1988), No Escape (1994), and The Doors (1991), in which he played drummer John Densmore.\n', '
Much of Dillon\'s 2000s work has been in television, including the CBS series That\'s Life as Paul DeLucca and the Fox series 24 as Lonnie McRae. He appeared in the 2006 film Poseidon, a remake of The Poseidon Adventure, and on Donald J. Trump\'s Fabulous World of Golf on The Golf Channel in April 2010.\n', '