Mark Harmon has played many memorable roles in his career, including playing secret agent Simon Donovan in The West Wing season 3. However, none of them have left a lasting impression like Leroy Jethro Gibbs in NCIS. Interestingly, it was the name “Leroy Jethro Gibbs” that made Harmon say yes to the role — not the script or the chance to join a long-running series.
In an interview with Fox News Digital, Harmon revealed:
“I read a lot of scripts, and when I read the name Leroy Jethro Gibbs, I was immediately drawn to it. At one point the character’s name was changed to Bob Robinson or something, and I immediately called and asked to change it. Someone said to me, ‘You can’t play a character named Leroy Jethro Gibbs,’ and I said, ‘Why not?’”
Harmon emphasized: “If that name wasn’t in the script, I don’t think I would have taken the role.”
For fans, the name Gibbs is more than just a title. It’s powerful, memorable, and perfectly fits the character’s cold, tough, yet humane demeanor. It’s hard to imagine that name being replaced by something “ordinary” like Bob.
Gibbs made his final appearance in season 19 episode 4, “The Great Wide Open,” when he said goodbye to his teammates and chose to live in seclusion in Alaska. Over the course of 19 seasons, viewers have followed a former Marine Corps sniper, a man who lost his wife and daughter, and who applied his own “rules of life” to each case. Gibbs was not only a skilled investigator, but also a symbol of steely spirit and loyalty.
Although the character Alden Parker (played by Gary Cole) has taken over Gibbs’s role, for many, Harmon’s departure still leaves a big void. Susan Bluestein — NCIS casting director — shared in an article for The Hollywood Reporter on the occasion of the show’s 20th anniversary:
“Casting was extremely difficult. I cast Mark Harmon as John Dillinger in a 1991 TV movie, and he was excellent. I always believed that Mark had the right talent to play Gibbs.”
Currently, fans can still follow Gibbs’ journey through 19 seasons on Hulu, or watch the entire series from seasons 1 to 22 on Paramount+. And if you want to explore Gibbs’ past, don’t miss NCIS: Origins — a prequel series with season 1 already airing and season 2 scheduled to premiere in late 2025, with Harmon himself taking on the role of narrator.
NCIS season 22 ended with the episode “Nexus” on May 5, 2025, and season 23 will continue in the fall. With a character like Gibbs, viewers always look forward to the return — even if only briefly — of the old captain with his steady eyes and quiet heart hidden behind iron principles.
