Mark Harmon Returns to NCIS After a Silent Exit — As a Series Regular This Time

Back in October 2021, Mark Harmon quietly walked away from NCIS after 18 seasons. There was no huge, explosive goodbye episode. Gibbs simply chose to stay behind in Alaska, and that was the end of an era.

Now, nearly four years later, he’s coming back.

Harmon announced on Instagram that he’s returning to the franchise as a main cast member for Season 3 of the prequel series, NCIS: Origins.

If you haven’t tuned in, NCIS: Origins follows a young Leroy Jethro Gibbs (played by Austin Stowell) during his early days at Camp Pendleton in the 1990s. Harmon has been narrating the series from the start, but Season 3 changes the game. He will now appear on screen as the older, present-day Gibbs, digging into a mystery that connects his past to his present.

This isn’t a direct continuation of his Alaska storyline on the main show, but it gives fans something just as exciting. It lets both the younger and older versions of Gibbs share the screen without stepping on each other’s toes.

The show made this possible because Austin Stowell did such a solid job making the younger Gibbs his own. Fans accepted him, which gave the creators the green light to bring Harmon back on camera without worrying he would steal the entire spotlight.

Harmon hasn’t said much about what convinced him to return. But committing to a full season with a central mystery isn’t just a quick cameo—it’s a major, carefully planned comeback.