While Mark is now known for his fabulous on-screen role as Leroy Jethro Gibbs on NCIS, he started off in a cereal commercial which he dubbed a bit "humiliating." The actor's father, Tom Harmon ...

Former NCIS star Mark Harmon recalled his first acting experience, starring in a Kellogg's commercial alongside his father Tom Harmon ...

Like father, like son. A chip off the old block. There are corny cliches and there are simple facts as real as a heartbeat. Actor Mark Harmon and his late father, Tom, a Gary sports legend, shared ...

The real reason Mark Harmon made the shocking decision to quit NCIS has been revealed. The 73-year-old actor played special agent Leroy Jethro Gibbs on the hit CBS show for almost 20 years before ...

Mark Harmon, who played Leroy Jethro Gibbs on NCIS, talked about the early premise for NCIS, which was real cases.

Meanwhile, his father, Tom Harmon, was an American football player, military pilot, actor, and sports broadcaster. Asked about his childhood, Mark told TV Insider: "My parents kept things real.

Mark Harmon was already aboard NCIS: Origins to executive produce and narrate the series, but now he'll also reprise Gibbs in the premiere.

Former NCIS star Mark Harmon recalled his first acting experience, starring in a Kellogg's commercial alongside his father Tom Harmon ...