Summary
The ensemble cast ofNCISis the secret saucethat has made the series one of the longest-running scripted shows on television. Throughout its 21 seasons, manymain characters leftNCIS,but they were skillfully replaced with new ones that kept the cast exciting. The show even lost the franchise’s heart when Leroy Jethro Gibbs actor Mark Harmon parted ways with the character in season 19. Despite that, the show has prevailed and is preparing forNCISseason 22.
Beyond theoriginalNCISMajor Case Response Team characters,NCIShas had many memorable guest stars. Frequently, guests are brought on the show to portray villains or to be wounded or killed in the heat of the action. But sometimes, those who appear in a one-off appearance become series regulars. This is the case for Sean Murray’s Timothy McGee and Brian Dietzen’s Dr. Jimmy Palmer, the only remaining series regulars who appeared inNCISseason 1.
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Season 11, Episode 2, “Past, Present, and Future”
Mark Harmon As Leroy Jethro Gibbs
Date Of Birth: June 04, 2025
Actor: The Leroy Jethro Gibbs actor was born Thomas Mark Harmon in Burbank, California. The actor gradually came to fame acting in various movie and television roles and had a robust career in both acting and football before his role in the series. That said,NCISis Mark Harmon’s most noteworthy acting role. Many of his acting parts before NCIS were doctor and detective roles, preparing him for the role of Jethro Gibbs. He’s also starred in notable films, including his portrayal of Ryan inFreaky Fridayalongside Jamie Lee Curtis and Lindsay Lohan.
1983-1986
1991-1993
1996-2000
Fear and Loathing in Las Vegas
1998
2002
2003
2003-2021
Leroy Jethro Gibbs
Character: Mark Harmon’s character is central toNCIS.He portrayed Special Agent in Charge Leroy Jethro Gibbs, the former team leader of the Major Case Response Team (MCRT) at NCIS Headquarters. As a central character intheNCISuniverse, Harmon’s character has also appeared inJAGandNCIS: New Orleans.
Peoplenamed Mark Harmon “The Sexiest Man Alive” in 1986 amid hisSt. Elsewherefame.
David McCallum As Dr. Donald “Ducky” Mallard
Date Of Birth: June 19, 2025
Actor: The Ducky actor was born David Keith McCallum in Glasgow, Scotland. In the 1960s,David McCallum gained popularity as Illya Kuryakin in the television seriesThe Man from U.N.C.L.E.The actor was also widely recognized for his role as Dr. Mallard onNCIS,which he portrayed untilDavid McCallum died at 90. He also had roles in films such asThe Great Escape(1963) andThe Greatest Story Ever Told(1965).
1963
1965
1964-1968
1972-1974
1979-1982
2003-2023
Donald “Ducky” Mallard
Character: David McCallum portrayed Ducky, the beloved medical examiner for the MCRT. His character was full of exciting wisdom that he bestowed on his colleagues, and he was a highly skilled technician in his craft. Following his retirement, Ducky became the NCIS Historian.
Michael Weatherly As Anthony “Tony” DiNozzo
Date Of Birth: August 07, 2025
Actor: The Special Agent Anthony DiNozzo actor was born in New York City.Michael Weatherly’s most prominent role was Tony DiNozzoinNCIS.However, the actor is known for other television series roles from before and after his stay on the police procedural, including his start onThe Cosby Show.After he leftNCISfollowing season 13, he starred as Dr. Jason Bull in the courtroom dramaBull.Michael Weatherly will reprise the role of Anthony DiNozzo inNCIS: Tony & Ziva.
1991
2000-2002
2003-2024
2016-2022
Jason Bull
Character: InNCIS,Anthony D. “Tony” DiNozzo Junior was the Senior Field Agent for Gibbs' team. He was second-in-command to Gibbs and led the team on rare occasions when he was absent. Tony eventually departed NCIS to raise his daughter Tali but appeared inNCISseason 21.
Pauley Perrette As Abigail “Abby” Sciuto
Date Of Birth: June 06, 2025
Actor: Pauley Perrette is an actor and singer born in New Orleans, Louisiana. She began acting on theABC Afterschool Specialsin 1994 and was a server at Cafe Nervosa in two episodes of Frasier season 4.Perrette’s most substantial role was inNCIS,portraying the forensic scientist Abby Sciuto. She has also appeared in noteworthy films such asAlmost Famous(2000) andThe Ring(2002). Before herNCISstint, Perrette was in a Los Angeles all-girl band called Lo-Ball.
1996-1997
2000
2001
2001-2002
24
2003-2018
2020
Jackie
Character: Pauley Perrette portrayed Abby Sciuto, the team’s chief forensic scientist. She provided the team with crucial intel on forensics, ballistics, and genetics, all while blaring hardcore or heavy electronic music and decked out in goth makeup and attire.
Sasha Alexander As Caitlin “Kate” Todd
Date Of Birth: July 06, 2025
Actor: The Caitlin Todd actor was born Suzana Drobnjakovic in Los Angeles, California. Before her role onNCIS,Sasha Alexander portrayed Gretchen Witter in season 4 ofDawson’s Creek.AfterNCIS,Alexander starred in the crime dramaRizzoli & Islesand was a regular character inShameless.AfterSasha Alexander leftNCIS,she also appeared in noteworthy films, including Jim Carrey’sYes Man(2008) andHe’s Just Not That Into You(2009).
2000-2001
2003-2005
2008
2009
2010-2016
2015-2016
Helene Runyon
Character: InNCIS,Sasha Alexander portrays Special Agent Kate Todd. Alexander’s character starts as a Secret Service agent in season 1, episode 1, “Yankee White,” but joins Gibbs' team at the end. The character was brutally murdered in the final moments of season 2.
Sean Murray As Timothy McGee
Date Of Birth: July 27, 2025
Actor: Sean Harland Murray was born in Bethesda, Maryland, at the Bethesda Naval Hospital. When he was 11,Sean Murray was an extra inMy Blue Heavenstarring Steve Martin and Joan Cusack. In 1993, Sean Murray made his first motion picture appearance playing Thackery in Disney’sHocus Pocus.Before stepping into the role of McGee onNCIS,Murray appeared inJAGseasons 4 and 6 as Ensign Terry Guitry and Danny Walden. Murray’s career is dominated by his two decades onNCIS.He is the stepson ofNCIScreator Donald P. Bellisario.
1993
Harts of the West
1993-1994
Timothy McGee
Character:Sean Murray portrays NCIS Special Agent Timothy McGeein the series. McGee was initially assigned to the Norfolk Naval base but joined the Gibbs team as a probationary agent after providing critical intel inNCISseason 1. McGee adds valuable computer skills to the team, with degrees from Johns Hopkins University and MIT.
Brian Dietzen As Dr. James “Jimmy” Palmer
Date Of Birth: June 14, 2025
Actor: Brian Dietzen was born in Barrington, Illinois, and moved to Colorado when he was young. His two-decade stint on NCIS dominates his career,but Brian Dietzen had a few other roles before being cast as Jimmy Palmer.Dietzen portrayed the drummer Owen in My Guide to Becoming a Rock Starand Eddie in the 2003 film From Justin to Kelly. Since acting on NCIS, Dietzen has co-written several episodes, making him one of theNCISstars who expanded their rolesin the series.
2004-2024
Dr. Jimmy Palmer
Character: Jimmy Palmer started as Ducky’s medical assistant toward the end ofNCISseason 1. After Dr. Mallard retires, Jimmy ultimately becomes the team’s chief medical examiner, responsible for performing the team’s autopsies.
Cote de Pablo As Ziva David
Date Of Birth: June 15, 2025
Actor: The Ziva David actor was born María José de Pablo Fernández in Santiago, Chile.Cote de Pablo’s breakout role was her Ziva characteronNCIS.Before that, she had just a few features on television, including a regular role inThe Jury.Since her time on the series, Cote de Pablo has been featured in several movies, includingThe Last Rites of Ransom Pride(2010) andThe 33(2015). The actor will reprise her Ziva role in the upcoming spinoffNCIS: Tony & Ziva.
2004
2006-2020
2010
2015
Jessica
Character: The Ziva character is introduced as a Mossad officer at the beginning of season 3 and has robust ties to Israel. She is the half-sister of Ari Haswari and the daughter of Mossad Director Eli David. Ultimately, she joins Gibbs' team beforeZiva fakes herNCISdeathin season 13.
Lauren Holly As Director Jennifer “Jenny” Shepard
Date Of Birth: August 06, 2025
Actor: Lauren Holly was born in Bristol, Pennsylvania. She’s had a massive career with noteworthy roles dating back to the 1990s.Holly’s breakout role was the small-town sheriff Maxine Stewarton CBS’sPicket Fences.In 1994, Holly was Mary inDumb and Dumberwith Jim Carrey, to whom she was briefly married. She also appeared inChicago Hopeseason 6 alongsideNCIS’Leroy Jethro Gibbs and Leon Vance starsMark Harmon and Rocky Carroll. She also voiced Chihiro’s mother in the English version of Hayao Miyazaki’sSpirited Away.
1992-1996
Dumb and Dumber
1994
1996
1999-2000
2005-2008
2013-2016
Dr. Betty Rogers
Character: Lauren Holly portrayed NCIS Director Jennifer Shepard onNCIS.She was the former partner and lover of Special Agent in Charge Leroy Jethro Gibbs. She was a capable yet empathetic director who worked with the MCRT team instead of regulating them. She is murdered at the end ofNCISseason 5.
Rocky Carroll As Director Leon Vance
Date Of Birth: July 09, 2025
Actor: The Leon Vance actor was born Roscoe Carroll in Cincinnati, Ohio.Rocky Carroll’s breakout role was as Joey Emerson inRoc,and he was also known at the time for playing Dr. Keith Wilkes in the CBS medical dramaChicago Hope.He played a supporting role inCrimson Tideand landed it big in 2008 when he became NCIS Director Leon Vance alongside hisChicago Hopeco-star Mark Harmon. Carroll credits Harmon for his landing the role.Leon Vance’s NCIS director roleextends to the otherNCISlocation-based spinoff shows.
1991-1994
1995
2008-2024
Leon Vance
Character: In the police procedural, Rocky Carroll portrays NCIS Director Leon Vance. Vance takes over after Director Shepard is killed in a shoot-out in season 5. He oversees the MCRT at NCIS Headquarters, and the teams inall theNCISspinoff shows.
