Mark Harmon is an American actor known for his roles on television shows such as "St. Elsewhere," "Chicago Hope" and "NCIS." He also appeared on "Reasonable Doubts" and had a several episode story arc on "The West Wing."
In the early 1980's, Harmon was a regular cast member on a short-lived prime time soap opera, "Flamingo Road," before he landed a role on "St. Elsewhere" in 1983. Harmon left the show in 1986, and the producers created a story line in which the character contracted HIV in order to write him out the show. This was one of the first times a major character on a television show became HIV-positive.
Harmon worked steadily in television and film in the late 1980s and early 1990s before he took a role on "Chicago Hope" from 1996 to 2000. Since 2003, Harmon has played agent Leroy Jethro Gibbs in "NCIS."
Harmon was born in Burbank, California in 1951. He attended the University of California, Los Angeles, where he was the starting quarterback for the football team. He made his debut as an actor in the mid-1970's, when he received guest roles on shows such as "Emergency!" and "Adam-12." He married Pam Dawber, an actress, in 1987. They have two children.