Main •
Austin Stowell as Special Agent
Leroy Jethro Gibbs, a newcomer to the Pendleton branch of the
Naval Investigative Service, the precursor to NCIS •
Mark Harmon reprises his role as the older Leroy Jethro Gibbs, a now-retired veteran NCIS agent who narrates the series •
Kyle Schmid as Special Agent
Mike Franks, a seasoned agent and leader of the team. Franks was played by
Muse Watson in the original series. •
Mariel Molino as Special Agent Cecilia "Lala" Dominguez, a former Marine determined to stand out in the male-dominated workplace •
Tyla Abercrumbie as Field Operation Support Officer Mary Jo Hayes, the self-described "Head Secretary in Charge" •
Diany Rodriguez as Special Agent
Vera Strickland, a tough, no-nonsense agent.
Roma Maffia played the character in the original series. •
Caleb Foote as Special Agent Bernard "Randy" Randolf, the team's golden boy •
Patrick Fischler as Special Agent in Charge Cliff Wheeler, head of NIS's Pendleton Office •
Julian Black Antelope as
Chief Medical Examiner Témet Téngalkat, an unfazed, experienced ME with the San Diego County Medical Examiner's Office who works alongside NIS; he is a member of the
Payómkawichum tribe and the uncle of Tish Kwa'la. •
Michael Harney as Richard Kowalski, Evidence Custodian, who used to be Army chaplain/POW during the
Korean War. • Daniel Bellomy as Herman "Herm" Daniels, an NIS agent acting as the Evidence Custodian's assistant •
Bobby Moynihan as Woodrow "Woody" Browne, a forensic analyst •
Ely Henry as Philip Elertson, a chemist who works with Woody • Matthew Henerson as Carl Loughlin, an NIS agent • Eric Normington as Roger Murphy, a former NIS agent who had a gambling problem • Aaron Wilton as Special Agent JJ Henneberry, an NIS agent • Marisa Baram as Gail Price, an NIS secretary •
Robert Taylor as
Jackson Gibbs, Jethro's father. The character was played by
Ralph Waite in the original series before his death in 2014. •
Gabriel Mann as Doug Westmont, a shady lawyer.
Guest •
DaJuan Johnson as FBI Agent Noah Oakley who works cases with the team and has a romantic past with Cliff Wheeler • Lucas Dixon as FBI Special Agent
Tobias C. Fornell.
Joe Spano played the character in the original series. • Claire Berger as Lara Macy. Lala's friend; military police investigator.
Louise Lombard played the character in the original series' future Special Agent in Charge at the Office of Special Projects in Los Angeles. •
Adam Campbell as
Dr. Donald "Ducky" Mallard, a liaison from D.C. headquarters and an old acquaintance of Gibbs.
David McCallum played the character in the original series before his death in 2023. Campbell reprises the role after portraying the young Ducky in four episodes of the original series. • Kelly Albanese as Julie Larsen, Lala’s Sister • Thomas Crawford as Dr. Walter Magnus, Medical Examiner with NIS Headquarters at the Navy Yard in D.C. and NIS Chief Medical Examiner before Dr. Donald "Ducky" Mallard.
Bob Newhart played the character in an episode of the original series. •
Shea Buckner as
Dwayne Pride, a Sheriff's deputy turned NIS probie assigned to the NIS office in Panama who has a turbulent history with Gibbs. Pride was the protagonist of
NCIS: New Orleans where he was played by
Scott Bakula. ==Episodes==