Mark Harmon Returns Full-Time as Gibbs in NCIS: Origins Season 3

Fans of the NCIS franchise have exciting news to celebrate—Mark Harmon is officially returning full-time as Leroy Jethro Gibbs in Season 3 of NCIS: Origins.

CBS confirmed the announcement on Instagram, revealing that Harmon will appear in all 10 episodes of the upcoming season. The network teased his return with the message: “The story he never told enters a new chapter…”

The new season will follow a present-day mystery connected to Gibbs’ time at Camp Pendleton during the 1990s. The season-long storyline promises plenty of action while exploring another chapter in the legendary agent’s life.

In addition to returning on screen, Harmon will continue serving as the series’ narrator and executive producer. Although Season 3 has been shortened to 10 episodes, viewers can expect Gibbs to play a central role throughout the entire season.

Harmon’s most recent appearance came during the NCIS: Origins crossover event in late 2025, where it was revealed that Gibbs was still living in Alaska with his canine companion. He also made a brief appearance in the show’s premiere episode.

Mark Harmon first introduced Leroy Jethro Gibbs during the JAG backdoor pilot in 2003 before leading NCIS for nearly two decades. He departed the flagship series during Season 19 but has remained closely involved with the franchise.

Meanwhile, Austin Stowell continues portraying the younger Gibbs in NCIS: Origins, joined by Kyle Schmid, Mariel Molino, Tyla Abercrumbie, Diany Rodriguez, and Caleb Foote.

Season 3 of NCIS: Origins is scheduled to premiere this fall, airing Tuesdays at 10 p.m. ET/PT.