Mark Harmon

Thomas Mark Harmon (born September 2, 1951) is an American actor and former football player. He is perhaps best known for playing the lead role of Leroy Jethro Gibbs on ''NCIS''. He has appeared in a wide variety of television roles since the early 1970s, including Dr. Robert Caldwell on ''St. Elsewhere'', Detective Dicky Cobb on ''Reasonable Doubts'', and Dr. Jack McNeil on ''Chicago Hope''. He also starred in such films as ''Summer School'', ''Prince of Bel Air'', ''Stealing Home'', ''Wyatt Earp'', ''Fear and Loathing in Las Vegas'', ''Freaky Friday'', and ''Chasing Liberty''.

Harmon played Secret Service special agent Simon Donovan in a four-episode story arc in ''The West Wing'' in 2002, receiving an Emmy Award nomination for the role.

Harmon's character of NCIS special agent Leroy Jethro Gibbs was introduced in a guest starring role in two episodes of ''JAG''. From 2003 to 2021, Harmon starred in the spinoff ''NCIS'' as the same character. Provided by Wikipedia