Has Mark Harmon’s Entire Family Worked on ‘NCIS’?

Mark Harmon’s family is as familiar with the entertainment industry as Harmon himself is. But how many members of the Harmon family contributed to his most popular show?

How many of the Harmons can you find on ‘NCIS’? ‘NCIS’ star Mark Harmon | Arturo Holmes/Getty Images

NCIS has become a bit of a family affair over the years. Harmon’s eldest son, Sean Harmon, was the first of his family to appear in the long-running series. Sean has portrayed a younger version of Harmon’s Jethro Gibbs on several occasions. He first appeared in the season 6 episode “Heartland” through flashbacks. Afterwards, portraying a young Jethro Gibbs became a tradition for Sean. He’d later appear in a couple more NCIS episodes like “Mother’s Day” and “Deliverance” to name a few. In an interview with Entertainment Tonight (via Express), Harmon reflected on his son’s involvement in NCIS, and how it came to be.