Mark HarmonThomas Mark Harmon (born September 2, 1951) is an American actor, producer and director. He is known for playing the lead role of Leroy Jethro Gibbs on NCIS (2003-2021), a role which has earned him six nominations at the People's Choice Awards including a win for Favorite TV Crime Drama Actor in 201FilmographyFreakier Friday (2025)Chasing Liberty (2004)Freaky Friday (2003)NCIS (2003)Wyatt Earp (1994)Chicago Hope (1994)Worth Winning (1989)The Presidio (1988)Stealing Home (1988)Summer School (1987)The Deliberate Stranger (1986)Goliath Awaits (1981)Comes a Horseman (1978)