NCIS: The Biggest Cast Exits

NCIS is one of TV's longest-running and most popular series, having debuted in 2003 and routinely topping the yearly most-watched lists during its more than two-decade existence. Since the procedural started off Season 22 with the uncertainty about whether Katrina Law's Jessica Knight was leaving the series, it feels like the perfect time to take a peek at the past. After all, almost 20 years after the show premiered, NCIS is still going strong, and the show has survived plenty of cast turnover to get where it is.

With some of the show's biggest stars moving on to other projects even while NCIS was on top, the CBS drama has persevered no matter who has departed the show. Here are some of the show's biggest departures throughout the years. And the good news? It doesn't look like Katrina Law's Jessica Knight is getting ready to join the list, which will make for a very interesting NCIS Season 22.

Sasha Alexander originally signed a six-year contract to star as Caitlin Todd on NCIS, but left after only two years because she found the filming schedule of the show too grueling. Todd, the team's profiler and Tony DiNozzo's first partner was written out in a very gruesome way that would end up leaving a mark on Gibbs and the entire team, but particularly her partner, DiNozzo – she was shot by Mossad double-agent and series antagonist Ari Haswari.

Cote De Pablo's Ziva David replaced Sasha Alexander's Caitlin Todd and became even more beloved. But De Pablo also exited the show because she didn't feel like the direction the show was taking her character. De Pablo's David wasn't just beloved on her own, she also became half of one of the show's most beloved ships — Tiva, aka Tony and Ziva. (The couple is getting their own Paramount+ spinoff, NCIS: Tony & Ziva.) After the entire team resigned from NCIS to protect Gibbs in Season 11, Ziva opted to return to Israel. Later, the team found out she and Tony had a daughter, Tali, and that Ziva has died — except she hasn't. She faked her death, and she makes a surprise return at the end of Season 16 and the beginning of Season 17.

Michael Weatherly's Tony DiNozzo exited the show in Season 13, two seasons after Ziva David left, to account for Weatherly being burnt out, and yet the show's whole reasoning for writing out DiNozzo was very much tied to Ziva, in a way that has now allowed for the spinoff that will focus on the two of them and their daughter. In Season 13 DiNozzo learned that Ziva was dead and that the two had a daughter, Tali. He then decided he must leave NCIS to take care of his daughter. Ziva's death didn't stick — she faked her death — but his desire to leave the agency and reunite with Ziva her did, and the two are, at this point, presumably living happily ever after in Paris. We will surely find out what they're up to when NCIS: Tony & Ziva premieres in 2025.

Pauley Perrette's Abby Sciuto was the chief forensic scientist for the NCIS Major Case Response Team. Perrette's quirky, goth character was beloved by audiences, so it came as a bummer when she left the show in Season 15 due to alleged personal issues with Mark Harmon, who played Leroy Jethro Gibbs. The show gave her a very good exit, though, with the character leaving the show to start a charity in honor of her friend Clayton Reeves, who passed away. The actress has recently stated that she is not interested in acting anymore, so it is unlikely we will ever see Abby Sciuto on NCIS ever again.

Emily Wickersham's Eleanor Bishop joined the team as a replacement for Cote de Pablo's Ziva David and departed seven seasons later, in Season 18. There has never been a reason given for Wickersham's exit, though the actress welcomed a baby shortly after she departed from the show and has not acted since. On the series, Bishop was a former NSA analyst, and her exit was framed as having to do with her time in the NSA — with the show revealing that she had leaked an NSA document before her time with NCIS. However, this was later revealed to be a ruse that allowed Bishop to go undercover after leaving NCIS in "disgrace."

Season 18 also saw the departure of Maria Bello's Jacqueline Sloane from NCIS. Bello simply didn't renew her contract after her three-year deal ended, though she has never given a reason why. In the show, Sloane was a former Lieutenant in the US Army, who served as the team's operational psychologist and had a very close relationship with Gibbs — one that was definitely romantic, as the two shared a kiss in Sloane's final episode. Her exit from the show saw her return to Afghanistan, telling Gibbs that she didn't belong behind a desk.

Perhaps the central character of NCIS, Mark Harmon's Leroy Jethro Gibbs exited the show in Season 19, because Harmon felt it was time to take a step back from the character he'd played for almost two decades. Harmon remained an executive producer on NCIS, however, and will be an executive producer and serve as narrator on NCIS: Origins, the prequel to NCIS which will focus on a young version of the character of Gibbs. On the show, Gibbs chose to retire and stay in Alaska, telling McGee that he felt a sense of peace he hadn't felt since the deaths of his wife Shannon and daughter Kelly.

David McCallum's Donald "Ducky" Mallard's departure in NCIS Season 21 might have been the most heartbreaking of all due to the actor's passing. McCallum, who was introduced as the chief medical examiner in the pilot episode of NCIS retired from his role as medical examiner in NCIS Season 15 but remained with the show in a limited capacity. McCallum sadly passed away in 2023, which led to NCIS writing out the actor in Season 21. In the show, Ducky also passed away, with NCIS honoring both McCallum and the character he played with an entire episode dedicated to his memory, including Michael Weatherly's Tony DiNozzo returning to the show for Ducky's funeral.