Mark Harmon returns to NCIS Origins as Gibbs for season 3
Mark Harmon is returning to NCIS: Origins for Season 3, reprising Leroy Jethro Gibbs in every episode of the CBS prequel. CBS announced the full-time on-screen comeback on June 30, 2026, linking present-day Gibbs to a season-long mystery rooted in his 1990s Camp Pendleton past — his biggest mark harmon ncis origins role since leaving the flagship series in 2021.
Key Takeaways
- Harmon will appear on screen in all Season 3 episodes, not just a one-off guest spot.
- The arc is a present-day mystery connected to Gibbs's early Camp Pendleton years in the 1990s.
- It builds on his 2024 series premiere cameo and a 2025 Veterans Day crossover with NCIS.
- Season 3 premieres Tuesdays at 10 p.m. ET/PT on CBS this fall.
- Harmon continues to narrate and executive produce the prequel alongside son Sean Harmon.
Why Is Mark Harmon Returning to NCIS: Origins Now?
CBS confirmed Harmon's return in a social media post on Tuesday, June 30, 2026, positioning the move as a full-time acting comeback within the NCIS universe for the 2026-27 season. Harmon played Gibbs for more than 18 seasons on the flagship series before leaving a few episodes into the 2021-22 season.
Since then, he has stayed connected to the franchise through NCIS: Origins, which CBS ordered straight to series in 2024. He narrates each episode and serves as an executive producer, but his on-screen appearances had been limited to brief cameos until now.
For fans tracking celebrity breaking news, the Season 3 commitment marks the first time his Gibbs character drives an entire season of the prequel.
What Will Gibbs's Season 3 Storyline Involve?
According to CBS, Harmon will anchor a present-day mystery tied to Gibbs's Camp Pendleton days in the 1990s. The action-packed story is designed to unfold across the full season rather than wrap in a single episode.
The Hollywood Reporter notes this heavily serialized approach is a notable shift for the NCIS franchise, which has built more than 1,100 episodes across seven series largely through self-contained procedural cases. Season 3 will follow a similar dual-timeline model to last season's crossover — but without involving the mothership NCIS show.
The narrative thread appears to have started in Season 2, when Harmon guest-starred in a Veterans Day crossover. Young Gibbs, played by Austin Stowell, investigated a small-town naval officer's death in the 1990s on Origins, while the same case was unexpectedly reopened in the present day on NCIS.
When Does NCIS: Origins Season 3 Premiere?
Season 3 of NCIS: Origins is scheduled to air Tuesdays at 10 p.m. ET/PT on CBS beginning this fall, per Deadline. The timing keeps the prequel in CBS's fall lineup alongside the broader NCIS franchise, which also includes NCIS: Sydney and the upcoming NCIS: New York.
This will be Harmon's third on-screen appearance on the spinoff, following the 2024 series premiere and the 2025 crossover — but the first time he is woven through every episode of a season.
Who Else Is Involved Behind and in Front of the Camera?
Austin Stowell continues to play the younger Gibbs in the early 1990s, years before the events of the flagship series. The cast also includes Kyle Schmid, Mariel Molino, Tyla Abercrumbie, Diany Rodriguez, and Caleb Foote.
David J. North is showrunner for Season 3. Executive producers include Mark Harmon, Sean Harmon, Michele Greco, and NCIS: Los Angeles alum Eric Christian Olsen. CBS Studios produces the series.