Mark Harmon has stunned NCIS fans with his final goodbye. On May 13, 2025, the 73-year-old actor announced he won’t return as Leroy Jethro Gibbs, ending his 22-year run. Harmon, who left as a regular in Season 19 but stayed on as an executive producer, wants to focus on new projects and family. “Gibbs will always be part of me, but it’s time to move on,” he said.

Fans flooded social media with grief, sharing favorite Gibbs moments and rules. His last episode in Season 19, “Great Wide Open,” where he stayed in Alaska, resurfaced as a bittersweet memory. “I grew up with Gibbs—22 years, and now he’s gone,” a fan tweeted. The hashtag #ThankYouMarkHarmon quickly trended as viewers mourned.

Harmon’s exit cuts the last link to the original NCIS cast, following David McCallum and Pauley Perrette’s departures. While Gary Cole leads as Alden Parker, some fans feel the show’s early magic is gone. “Mark Harmon was NCIS,” a Reddit user wrote, though others hope the series can still thrive.

As Season 22 airs, showrunners may plan a tribute episode, possibly using archival footage of Gibbs. For now, fans are heartbroken, cherishing Gibbs’ lessons of leadership and justice. “We’ll miss you, Boss,” a fan posted, capturing the fandom’s shared sorrow.