Thomas Mark Harmon is an American actor and producer who has worked in television, film, and theater. Born on September 2, 1951 in Burbank, California, Harmon turned down professional football to pursue acting. He worked odd jobs between acting gigs, including as a carpenter and shoe company rep, and appeared in Coors beer commercials. Harmon is best known for his role as Leroy Jethro Gibbs on the CBS crime series NCIS from 2003 to 2021.