Who was on NCIS from the beginning? Only one of the original cast is still in the credits more than two decades on
NCIS premiered on CBS in September 2003 with five names in the main titles. Twenty-three seasons later, only one of them still turns up for work — and the man usually called an original cast member technically wasn't one.
NCIS has now run long enough to outlive most of its own leads, its lead's replacement, and its director. Of the five names in the 2003 main titles, exactly one is on the season 24 call sheet.
The original five
The show began as a two-part backdoor pilot inside JAG — "Ice Queen" on 22 April 2003 and "Meltdown" a week later, both written by Donald P. Bellisario and Don McGill. Bellisario decided the third agent in that pilot, Vivian Blackadder (Robyn Lively), was too soft for the series, so she was dropped and never mentioned again.
Navy NCIS proper premiered on 23 September 2003, with a main cast of five:
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- Mark Harmon as Leroy Jethro Gibbs — seasons 1 to 19, with his last regular run ending four episodes into 2021. Season 20 was the first without his credit.
- Sasha Alexander as Kate Todd — written out at the end of season 2 in 2005, with Cote de Pablo's Ziva David arriving in her place.
- Michael Weatherly as Tony DiNozzo — left after season 13 in 2016.
- Pauley Perrette as Abby Sciuto — left after season 15 in 2018.
- David McCallum as Ducky Mallard — a regular into season 20; he died on 25 September 2023.
The McGee technicality
Sean Murray was in season 1 as computer specialist Timothy McGee, but as a recurring guest rather than a series regular; he was promoted to the main titles for season 2. That's why some tallies count him among the originals and some don't. Either way, he has been there since 2003, and after McCallum's death he became the longest-serving member of the main cast.
Brian Dietzen, who plays Jimmy Palmer, joined late in season 1 on the same recurring footing and is also still in the show, which makes the "only one original" line a question of where you draw the credit.
"The longer we've been around, the longer people have kind of really gotten to know these characters," Murray told Entertainment Weekly in 2023, crediting the audience's protectiveness for the run.
What's happened lately
Season 23 ran from 14 October 2025 to 12 May 2026 across 20 episodes, and it removed another fixture. The 500th episode, aired on 24 March 2026, killed Director Leon Vance, ending Rocky Carroll's 18-season, 392-episode stint. Carroll told TVLine he wasn't behind the decision and only found out two episodes before it was shot, in late November 2025.
"It is never easy to say goodbye to any of our characters," showrunner Steven D. Binder said, describing the choice as giving Vance's life so the agency could continue.
CBS renewed the series on 22 January 2026, alongside NCIS: Origins and NCIS: Sydney, with season 24 due in autumn 2026 in the Tuesday 8pm slot. The returning regulars are Murray, Wilmer Valderrama, Katrina Law, Dietzen, Diona Reasonover, and Gary Cole.
One original is coming back
On 1 July 2026, Michael Weatherly was announced for a season-long arc as Tony DiNozzo, ten years after leaving. He told a UK fan convention on 12 July that season 24 won't undo the events of NCIS: Tony & Ziva, and that he was due to shoot his return scenes two days later.
Which means that for the first time since 2016, two of the original 2003 cast will be in the same episode — and one of them has been there the whole time.
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