Is Mark Harmon returning to NCIS? Here’s everything you need to know

Mark Harmon is officially returning to the NCIS universe as Leroy Jethro Gibbs for the first time since his 2021 departure. CBS confirmed that Harmon will make a special guest appearance during the upcoming NCIS and NCIS: Origins crossover event, airing on Veterans Day, November 11, 2025.

The two-hour event will begin with NCIS: Origins. Young Gibbs (Austin Stowell) and his team investigate the 1990s death of a naval officer. The case will later be reopened in the present day on NCIS. Harmon, who also serves as executive producer and narrator on Origins, last appeared briefly in its pilot episode.

Co-showrunners David J. North and Gina Lucita Monreal revealed that Gibbs is “no longer alone.” Harmon said he was drawn to the new storyline and felt it was the right time to revisit the beloved character.

Everything to know about Mark Harmon’s long-awaited NCIS return

Mark Harmon is officially stepping back into the world of NCIS as Leroy Jethro Gibbs. The actor left the CBS drama in 2021, and has not been a part of the show for four years. He will reprise his iconic role during a special NCIS and NCIS: Origins crossover event airing on Veterans Day, November 11, 2025. The announcement thrilled fans who have missed Gibbs since he retired to Alaska.

According to Deadline dated October 28, 2025, co-showrunners and executive producers David J. North and Gina Lucita Monreal said in a statement,

"Four years ago, Gibbs disappeared to Alaska to live a life of solitude. We know how much fans have missed seeing Mark and have wondered what Gibbs is up to today."

They also said,

"Well, on Nov. 11, we’re so excited to announce that Mark Harmon will return as Leroy Jethro Gibbs in the Origins hour of the NCIS crossover event. We don’t want to give too much away, but let’s just say Gibbs is no longer alone."

Harmon added,

"I’m very proud of the storytelling that David and Gina are doing on Origins. They continue to push boundaries and dive deeper into the characters’ backstories."

He continued,

"They came to me with an idea for Gibbs that I liked, and it seemed like a good time to check in with him. I hope fans enjoy it."

Harmon continues to serve as executive producer and narrator for NCIS: Origins. The prequel follows a young Gibbs (Austin Stowell) in the early 1990s. Fans can expect his appearance to bridge the emotional gap between Gibbs’ past and present. 

Inside Gibbs’ return: How NCIS and NCIS: Origins collide

The upcoming collaboration between NCIS and NCIS: Origins will bring the two shows together through a decades-spanning investigation. The special two-hour event will begin with NCIS: Origins at 8 p.m. ET. It will be followed by NCIS at 9 p.m. ET, airing in chronological order for one night only.

In Origins, set in the 1990s, a young Gibbs (Austin Stowell) and his NIS team investigate the mysterious death of a naval officer in a small town. The case appears to have long been closed. That is until new evidence brings it back into focus in the present day. The story then continues on NCIS, where the modern team reopens the decades-old investigation. They uncover unexpected links to Gibbs’ early career and his mentor, Mike Franks.

Mark Harmon’s return as the older Gibbs will occur during the Origins hour. It will reveal what his life has been like since retreating to Alaska in 2021. With both teams working on the same case from different eras, the event promises to deepen Gibbs’ legacy. It will also explore how the choices of his younger self continue to shape the man fans know today.

Stay tuned for updates on the latest TV shows.