It’s official: Mark Harmon is coming back to NCIS. Well, sort of.
The longtime actor famously starred as Leroy Jethro Gibbs for NCIS’ first 19 seasons, making him a staple on the hit CBS franchise. While Mark has helped the network develop a Gibbs prequel series (NCIS: Origins) and reprised his role in November 2025, fans rarely get to see him as Gibbs anymore.
Well, Mark is delving back into the world of NCIS, albeit in a way fans weren’t expecting. As the show’s official Instagram revealed on May 4, the actor will appear on the NCIS: Partners and Probiespodcast on May 5. Mark will bring Leon Carroll Jr. with him to promote the new book that they co-authored, Ghosts of Sicily: The True Story of the Naval Intelligence Agents Who Courted the Mob to Fight Nazis in America and the Battlefields of Italy.