CBS today announced that NCIS fan-favorite Mark Harmon will return as Leroy Jethro Gibbs in the next chapter of the iconic character’s story this fall. After portraying Gibbs for 18 seasons on NCIS, Harmon is set to appear in ALL episodes of the upcoming third season of NCIS: Origins, the NCIS prequel series. He will reprise his role a present-day mystery connected to his 1990s Camp Pendleton years unfolds across a season-long storyline.
Harmon, who serves as executive producer on the series, also narrates each episode. He previously appeared as Gibbs in the NCIS: Origins 2024 series premiere and made a special guest appearance during the first crossover event between NCIS and NCIS: Origins in November 2025.
CBS made the announcement on social media today:
NCIS: Origins follows a young Leroy Jethro Gibbs (Austin Stowell) in the early ‘90s, years prior to the events of NCIS. Also starring are Kyle Schmid, Mariel Molino, Tyla Abercrumbie, Diany Rodriguez and Caleb Foote.
Season 3 will air Tuesdays at 10:00 PM, ET/PT this fall on CBS and streaming on Paramount+.
_