Highlights

• Fans were left shocked by Harmon's decision to leave NCIS after being with the show since 2003.
• Harmon's character Gibbs, is the heart of NCIS, making it hard to imagine the show without him.
• Harmon was seen as a mentor by many NCIS stars, but had a strained relationship with former co-star Pauley Perrette.

Mark Harmon shocked fans with his decision to leave the CBS drama NCIS. Up until his exit, Harmon had been one of the few cast members who had been with the show since it first aired in 2003. At the same time, Harmon had also been serving as an executive producer on the hit show since 2011. Hence, no one ever imagined that he would decide to leave while the series continued.

As fans know, this isn’t the first time that a major star has departed the crime procedural. However, with Harmon’s Agent Leroy Jethro Gibbs being the heart of the show, it’s quite impossible to imagine NCIS without him. And while Gibbs and his team regard each other as family in the series, there have been questions about whether the cast truly get along in real life. Especially in recent years, many have wondered whether Harmon has a good relationship with all of his NCIS co-stars.

Updated March 2024: It turns out that Mark Harmon will not be returning to 'NCIS' anytime soon. However, it was announced early March 2024, that Harmon's iconic character, Leroy Jethro Gibbs is getting his own spin-off, 'NCIS: Origins'. Harmon will be executive producing the show. He will also serve as the narrator. Additionally, Michael Weatherly and Cote de Pablo will be returning for a spin-off of their own, revolving around their character, Anthony DiNozzo and Ziva David.

A Lot Of NCIS Stars Looked Up To Mark Harmon

Mark Harmon was seen as a mentor to many of the stars on NCIS

Harmon had been a veteran actor long before he came to NCIS. In fact, he’s been around since the 70s, taking on a variety of TV roles in shows such as Sam, Centennial, 240-Robert, Flamingo Road, St. Elsewhere, Chicago Hope, The West Wing, and Harts of the West, where he first met NCIS co-star Sean Murray. Even then, Murray was in awe of Harmon. “I’ll never forget. That’s where I first met Harmon,” Murray told Country Living. “And he made an impression on me even back then.”

As for Cote de Pablo, who famously plays Ziva on the show, the actor saw Harmon as a “mentor.” “[Mark Harmon] is more of a friend mentor. He was always like a father figure to me,” the actress explained during an appearance on BUILD. “Obviously, Ziva and Gibbs have that but Cote and Mark have that as well.”

Meanwhile, former NCIS star Michael Weatherly said that working with Harmon helped him prepare to lead his own CBS drama, Bull. “It’s been very illuminating and given me a great deal of insight and regard for what Mark Harmon was doing all those years (on ‘NCIS’),” the actor told USA Today. “When I was like, ‘How come he doesn’t have as much fun as the rest of us?’”

That said, Weatherly also revealed that he and Harmon never really became close, even after spending several years on the show together. After all, they had always been polar opposites. “Mark Harmon and I were on different poles. I was Antarctica, he was the North Pole ...,” he told The Futon Critic. “And he was confused by my presence right from the get-go.”

That said, Weatherly also said that they parted on good terms when he left NCIS. “He was pretty succinct,” he told Parade. “He said, 'Thank you and good luck,' which I adored the simplicity of and appreciated deeply that he was giving his handshake and support.”

However, This Former NCIS Star Also Once Called Mark Harmon Out

Pauley Perrette and Mark Harmon had a poor working relationship

While Harmon seems to have a good relationship with several of the show’s stars, it seems the actor didn’t get along well with former NCIS star Pauley Perrette, who left the show in 2018. And while the relationship between Harmon’s Gibbs and Perrette’s Abby looked closer than ever onscreen, Perrette revealed things got really frosty between them behind the scenes.

Following her exit, numerous stories were released about why Perrette left the show. Eventually, reports emerged that an incident took place on the set of the series.

According to reports, a crew member ended up getting 15 stitches after Harmon’s dog bit him. Meanwhile, Perrette became furious and called out Harmon. Since then, the two have decided to stay out of each other’s way. In fact, they refused to film scenes together.

Since leaving the show, Perrette has also left cryptic posts on Twitter, alluding to her feud with Harmon. “No morals, no obligation to truth, and I'm just left here, reading the lies, trying to protect my crew,” the actress once wrote in one post. “Trying to remain calm. He did it.”

Meanwhile, in another post, Perrette also said that she left the show following “Multiple Physical Assaults.”

Harmon has never responded to any of Perrette’s accusations.

Will Mark Harmon Ever Return To NCIS?

With the twenty-first season underway in 2024, Mark Harmon has yet to return

On the show, Gibbs may have told McGee (Murray) that he wasn’t going back. However, fans may be glad to know that a return in the future hasn’t been ruled out completely. In fact, showrunner Steven D. Binder is choosing to stay optimistic.

“As an executive producer and dear friend, Mark continues to be an integral part of the fabric of the show,” Binder said in a statement. “So regarding the future of Gibbs, as long-time fans of the show may have noticed over the years … never count Leroy Jethro Gibbs out.”

NCIS is currently in its twenty-first season and thus far, Harmon has yet to return.