Mark Harmon is an American actor who’s currently best known for his role as Leroy Jethro Gibbs in the CBS series NCIS. He started starring on the show in 2003 and still does up to present. Prior to that, he starred as Dr. Jack McNeil in the medical drama series Chicago Hope. He also received critical praise for his 4-episode stint as Simon Donovan in The West Wing, a role which earned him a Primetime Emmy nomination. Other notable performances on TV were as Detective Dicky Cobb in Reasonable Doubts and Dr. Robert Caldwell in St. Elsewhere. In the 2000s, he had supporting roles in the films Freaky Friday, Chasing Liberty, and Weather Girl.