'NCIS' Cast Then and Now

'NCIS' Cast Members

The original NCIS cast keeps growing, with some stars popping in for single seasons and others on the series for 20 years.

The cast could have been much different, with A-list names like Harrison Ford and Jennifer Aniston initially floated for the characters of Gibbs and Katie, but no one can deny the chemistry that the series created with its roster.

From OG series regulars to recurring roles to current cast members, find out what your favorite NCIS stars are doing now.

NCIS Cast Then and Now

Mark Harmon

Mark Harmon starred in the backdoor pilot episodes of JAG that led to its spinoff, NCIS. He led the cast of NCIS for 18 full seasons as Supervisory Special Agent Leroy Jethro Gibbs and became an executive producer on the series in 2008. He exited the series in Season 19, Episode 4, "Great Wide Open."

"The longest time I ever spent anywhere at any one time was five years on Chicago Hope," Harmon said after his character was written off the series. "This show is still doing what it's doing after 19 years and remains remarkable. I don't know that it will ever happen again. I'm proud of this show and I’m proud of the people here. This group, this family, this team has been through a lot and being part of this show for as long as most of us have been here, I’m proud of that and the people who jumped onboard as well."

Following Harmon's exit from the show, he worked with the series' technical advisor, an actual former NCIS agent Leon Carroll, Jr., on the book Ghosts of Honolulu: A Japanese Spy, A Japanese American Spy Hunter, and the Untold Story of Pearl Harbor.

Pauley Perrette

Pauley Perrette was a fan favorite as the quirky, mall goth forensics specialist Abbey Sciuto, and the role was a special one for her: She studied criminal science before becoming an actor. She played Abby for the first 15 seasons of NCIS, then starred in the series Broke in 2020, which was unfortunately canceled after a single season.

David McCallum

A veteran of the crime and action genre from his days on The Man From U.N.CL.E. series, David McCallum starred as the NCIS chief medical examiner Dr. Donald "Ducky" Mallard since Season 1. McCallum died on Sept. 25, 2023, at age 90.

“For over 20 years, David McCallum endeared himself to audiences around the world playing the wise, quirky, and sometimes enigmatic, Dr. Donald ‘Ducky’ Mallard,” NCIS executive producers Seven D. Binder and David North said in a statement. “But as much as his fans may have loved him, those who worked side by side with David loved him that much more. He was a scholar and a gentleman, always gracious, a consummate professional, and never one to pass up a joke. From day one, it was an honor to work with him and he never let us down. He was, quite simply, a legend. He was also family and will be deeply missed.”

Michael Weatherly

Michael Weatherly starred as Senior Field Agent Anthony DiNozzo from Season 1 to 13, then left to star in Bull from 2016 to 2022.

Weatherly was accused of sexually harassing Eliza Dushku on the set of Bull, leading CBS to pay her a $9.5 million settlement. When the allegations went public, Weatherly said in a statement, "When Eliza told me that she wasn't comfortable with my language and attempt at humor, I was mortified to have offended her and immediately apologized."

Bull ended in 2022.

Related: Will DiNozzo Come Back to NCIS?

Sasha Alexander

Sasha Alexander starred in the first two seasons of NCIS as Caitlin Todd until her character was killed off. She went on to star in TNT's Rizzoli & Isles and Shameless, and later directed an episode of Netflix thriller You.

Sean Murray

Sean Murray was a recurring star as Senior Field Agent Timothy McGee in Season 1 before being bumped up to a series regular in Season 2. Murray is the stepson of NCIS co-creator and co-executive producer Donald Bellisario.

Related: NCIS Star Sean Murray on Working With His Daughter to Solve a Murder

Cote de Pablo

Though she's actually of Chilean descent in real life, Cote de Pablo is best known for playing former Israeli Mossad agent Ziva David in NCIS. She was a series regular from Season 3 until Season 11, after which she said she left because she didn't think the scripts were that great anymore. It was believed that her character died offscreen, but in Season 16, she made a surprise guest appearance, in which it was revealed that Ziva was alive and had been in hiding. She recurred on the show again in Season 17.

Related: Inside Cote de Pablo's Return to NCIS

Lauren Holly

Lauren Holly starred as NCIS director and Gibbs' ex-girlfriend Jenny Shepard from Seasons 3 through 5. Holly previously co-starred with Harmon and Rocky Carroll in Chicago Hope. She's worked steadily on guest roles and cameos since her character was killed off of NCIS, including starring as Mimsy in The Lake.

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Rocky Carroll

Rocky Carroll began his NCIS tenure as a recurring guest star in Season 5, playing NCIS director Leon Vance. In Season 6, he was upped to a series regular, with his character taking over for Holly's Jenny Shepard.

In addition to his work on NCIS, he's also directed an episode of Magnum P.I., starred in the TV movie The Immortal Life of Henrietta Lacks and lent his voice to several animated projects and video games.

Related: Rocky Carroll Tells All on Directing NCIS

Emily Wickersham

Emily Wickersham's role of Eleanor Bishop started as an NSA agent in a Season 11 guest role. After de Pablo's exit, Wickersham was upped to a series regular, and eventually Bishop was promoted to an NCIS agent. She left NCIS after Season 18 in 2021 and has stayed mostly under the radar since.

Duane Henry

Duane Henry debuted on NCIS in Season 13 as a guest star, then became a series regular until Season 15. His character, Clayton Reeves, was killed off in Season 15, Episode 22, "Two Steps Back," in part because no one was sure how to develop his character after the death of NCIS co-creator and showrunner Gary Glasberg in 2016.

Related: Duane Henry on Life After NCIS

Wilmer Valderrama

Wilmer Valderrama debuted on NCIS as NCIS Special Agent Nicholas "Nick" Torres in Season 14 and remains on the series today. Valderrama's breakout role was as Fez on That '70s Show, a role he reprised in Netflix's That '90s Show. He also voiced several animated characters, including the titular Handy Manny, Gaxton in Disney's Onward and Agustín Madrigal in Encanto.

Related: Wilmer Valderrama's Net Worth Revealed

Maria Bello

Already an acclaimed actress before joining NCIS, Maria Bello starred as Dr Jacqueline "Jack" Sloane, an operational psychologist and agent, from Season 15 to Season 18. Since her 2021 exit, Bello served as a producer and writer on The Woman King, a criminally underrated drama starring EGOT-winner Viola Davis, and starred in Netflix's acclaimed Beef.

Brian Dietzen

Brian Dietzen has been on NCIS since Season 1 as Dr. Jimmy Palmer, upping from a recurring role to a series regular. He's also written for the series.

Dietzen suffered a stroke in 2020 and underwent heart surgery. He's since fully recovered.

Related: Stream 'NCIS' on FUBO TV

Diona Reasonover

Diona Reasonover stars as NCIS Forensic Specialist Kasie Hines, beginning as a recurring character in Season 15 and moving up to a series regular. Reasonover is also a writer on the show.

Next, Find Out Who's Back for NCIS Season 21