NCIS: Origins fans were shocked when, at the end of June, it was revealed that Mark Harmon is not only returning to the prequel for its third season but will appear in every episode. He is an executive producer and has been narrating as the present-day Gibbs (with Austin Stowell playing the younger version onscreen) and has appeared onscreen twice over its first two seasons.
Harmon’s major NCIS: Origins Season 3 role is, according to CBS, “part of a present-day mystery tied to his ‘90s Camp Pendleton days in an action-packed story that unfolds all season long.” No other details have been released.
Given his previous appearances have been short, below, we’re gathering everything you need to know heading into seeing present-day Gibbs onscreen for this arc.
When did Mark Harmon leave NCIS?
Harmon’s last episode as a series regular on the mothership, where he starred as Leroy Jethro Gibbs since the beginning (and in the two JAG episodes that served as a backdoor pilot), came in Season 19 Episode 4. He remains an executive producer on NCIS.
Why did Mark Harmon leave NCIS?
Harmon addressed his exit in July 2024. “I always paid attention to the writing room on that show creatively. It wasn’t so much a decision to leave as it was maybe just the right timing to push away a little bit,” he told Parade nearly three years after his final NCIS episode ahead of Origins‘ debut. “I was thrilled with the storyline they came up with and how they handled the character. And the show’s continued on. I was always of the opinion that this show would carry on, no matter who left or who joined.”
CBS
How was Mark Harmon’s Gibbs written out of NCIS?
Gibbs was already without his badge when he and McGee (Sean Murray) headed to Alaska for an investigation in Season 19 Episode 4, titled “Great Wide Open.” (He’d lost his badge when he was suspended for beating up and only regretting not killing a man who was running a dogfighting ring and killing the losers in Season 18. When they wrapped the case, Gibbs dropped the shocking news on McGee that he wouldn’t be returning to D.C. with him but was instead staying in Alaska.
As he told the senior field agent, “My gut’s telling me I’ll know when I find [what I’m looking for].” Gibbs didn’t know if he’d find it in Alaska, he continued, but “whatever I’m feeling, this sense of peace, I have not had this since Shannon and Kelly died, and I’m not ready to let it go.” Before McGee left, he asked his former boss to promise he’d be OK. “I already am,” Gibbs said.
How did Mark Harmon appear onscreen on NCIS: Origins?
While Harmon narrates every episode of the spinoff, he’s only appeared onscreen in two so far. He guest-starred in the series premiere, sitting by a campfire to bookend the episode. He then appeared in Origins‘ half of the NCIS crossover during the prequel’s second season. We caught up with him, still in Alaska, with an evacuation order coming over the radio. He’d been joined by a dog he found in the middle of nowhere with a storm approaching.
Did Mark Harmon return to NCIS in Season 23?
No, but he did return to the D.C. area to help Parker (Gary Cole) get revenge following Vance’s (Rocky Carroll) death in the 500th episode. In Season 23’s penultimate episode, former Army CID director Rogers (J. Paul Boehmer), who’d been part of the arms trafficking ring Vance died taking down, made a deal for witness protection, only to be killed “the Gibbs way,” a.k.a. by a sniper from 4500 feet away, a shot that very few people could make. While it’s never explicitly said that Gibbs was involved, Parker did have salmon, fresh from Alaska, in the final scene of the episode.
NCIS: Origins, Season 3, Fall 2026, Tuesdays, 10/9c, CBS