NCIS: The Actors Who Almost Played Gibbs Before Mark Harmon

"NCIS" became a small screen success in short order, stepping out from the shadow of its predecessor, "JAG," and then some. The program has been a beloved part of the crime procedural genre since 2003 and has brought viewers numerous iconic stories and characters in that time. Arguably the most recognizable of them all is Agent Leroy Jethro Gibbs (Mark Harmon), who leads the Naval Criminal Investigative Service from Season 1 to Season 19. As the face of the program, Harmon cemented his legacy as a television icon, though that spot could've gone to any one of multiple different actors.

Speaking to The Hollywood Reporter for an oral history of "NCIS," casting director Susan Bluestein said that names such as Alec Baldwin, Chris Cooper, Clive Owen, Kevin Bacon, Tom Berenger, Val Kilmer, Charlie Sheen, Aidan Quinn, and Patrick Swayze were all considered for the role. However, offers weren't made to any of these actors. Meanwhile, Andrew McCarthy met with "NCIS" creator Donald P. Bellisario to discuss the part, and Scott Glenn had it offered to him, but he turned it down in the end. Eventually, Harmon's name came up in conversation, and the rest is history.

In no time, Harmon's take on Gibbs became a vital piece of the "NCIS" puzzle — so much so that when he bid the series farewell, concerns arose over its longevity.

After beating out some pretty high-profile names to score the role, Mark Harmon enjoyed an incredible tenure as Gibbs. During his run, he was credited for a staggering 435 episodes and won over "NCIS" fans around the world. Therefore, when he made the decision to leave the character and program behind, it came as a shock and his exit drastically changed the presentation of the show. In fact, the minds behind the hit drama were worried that it wouldn't survive without Harmon leading the charge week after week.

"We thought [Harmon leaving] was the death knell. Coming in at 6:30 a.m., five days a week, and being the major character that was the linchpin," executive producer Charles Floyd Johnson told Hollywood Reporter. This was an entirely logical fear to have, seeing as Harmon and Gibbs had become so tightly woven into the show's identity over nearly two decades. Ultimately, the powers that be brought in Gary Cole as Agent Alden Parker in hopes of filling the void, marking the start of a brand new "NCIS" era.

Mark Harmon may not have been the first choice for Gibbs, but considering his remarkable "NCIS" tenure and how he made his character a TV favorite with ease, he was certainly the right one.