The Untold Story of Who Almost Became NCIS’s Leroy Jethro Gibbs

Mark Harmon is the heart and soul of NCIS. His portrayal of Leroy Jethro Gibbs turned the show into a primetime powerhouse. But what if another actor had taken the role instead? Believe it or not, 11 actors were seriously considered before Harmon landed the part—and some of them are Hollywood legends, including two Oscar winners!

Let’s take a deep dive into the actors who almost became the face of NCIS.

The Importance of Casting the Right Gibbs

Casting Gibbs wasn’t just about finding a good actor—it was about finding someone who could command respect, show emotional depth, and carry the entire series on his shoulders. The perfect Gibbs needed to be tough yet compassionate, intimidating yet deeply human.

Here’s a look at the actors who were considered for the role before Mark Harmon made it his own.

1. Harrison Ford – The Hollywood Icon Who Passed on Gibbs

Yes, Indiana Jones himself was in the conversation for Gibbs! Harrison Ford has that tough-but-fair persona that would have made him a great fit. However, Ford was more focused on movies at the time and wasn’t ready to commit to a TV series.

2. Don Johnson – The ‘Miami Vice’ Star Who Could Have Been Gibbs

After Miami Vice, Don Johnson was a huge name in television. Producers saw him as a potential Gibbs, but he wasn’t quite the right fit. Plus, he moved on to star in Nash Bridges, another crime procedural that likely kept him from taking the NCIS role.

3. Kevin Costner – An Oscar Winner Who Almost Led ‘NCIS’

Could you imagine Kevin Costner as Gibbs? The Dances with Wolves star was reportedly considered, but at the time, he was still focused on major Hollywood films. Today, he’s made the jump to TV with Yellowstone, proving he could have been a great Gibbs.

4. Mel Gibson – A Controversial Choice That Didn’t Happen

Gibson’s action-hero persona could have brought a unique edge to Gibbs, but his big-screen success likely made him too expensive and unavailable. Plus, his reputation at the time may have been a concern for network executives.

5. Tom Selleck – Another TV Legend Who Almost Took the Role

With his history in crime procedurals (Magnum P.I. and later Blue Bloods), Tom Selleck had the perfect presence for Gibbs. However, he was already committed to other projects and ultimately passed on the opportunity.

6. Alec Baldwin – The Smooth-Talking Star Considered for the Role

Alec Baldwin was another name on the list, thanks to his commanding presence and serious acting chops. But his focus on film and stage roles kept him from signing on for a long-term TV commitment like NCIS.

7. Dennis Quaid – The Movie Star Who Was Almost Gibbs

Quaid had the right balance of charm and authority, making him a strong contender. However, his schedule was packed with film projects, preventing him from locking in a long-term TV role at the time.

8. Kurt Russell – An Action Star Who Would Have Brought a Different Energy

Kurt Russell is known for his rugged, tough-guy roles, which could have made for a grittier version of Gibbs. However, Russell rarely does TV, and committing to a long-running procedural wasn’t on his radar.

9. Michael Madsen – The Tarantino Favorite Who Was in the Running

Madsen’s deep, gravelly voice and no-nonsense attitude could have made him an interesting Gibbs. However, his reputation as a “tough guy” in Hollywood might have made him a bit too intense for the role.

10. Sam Neill – The Unexpected Name on the List

Best known for Jurassic Park, Sam Neill was also considered for Gibbs. His calm yet commanding demeanor could have worked well, but he preferred film work at the time and turned it down.

11. Jeff Bridges – Another Oscar Winner Who Almost Led ‘NCIS’

Bridges is a Hollywood legend, and his rugged charm could have made him an excellent Gibbs. However, much like Kevin Costner, he wasn’t looking for a long-term TV commitment back then.

Why Mark Harmon Was the Perfect Choice for Gibbs

After considering all these big names, CBS ultimately landed on Mark Harmon—and it was the best decision they could have made.

Why? Because Harmon had everything Gibbs needed:
– A commanding presence
– A background in crime dramas (The Presidio, Chicago Hope)
– The ability to balance toughness with warmth
– A dedication to long-term TV work

Unlike many of the other actors on this list, Harmon wasn’t tied down by Hollywood’s film industry, making him a perfect fit for the lead role.

How ‘NCIS’ Became a TV Powerhouse with Harmon at the Helm

With Harmon as Gibbs, NCIS became one of the most successful shows in television history. The series spawned multiple spin-offs and maintained a loyal fanbase for over two decades.

Would the show have had the same success with another actor? Maybe. But it’s hard to imagine NCIS without Mark Harmon’s steady, no-nonsense portrayal of Gibbs.

Final Thoughts

Casting a role like Gibbs is no easy task, and looking at this list, it’s clear that NCIS could have been a very different show if someone else had taken the lead. While some of these actors might have been great, Mark Harmon was the right choice—and the show’s long-lasting success proves it.

Who do you think would have made a great Gibbs if Harmon hadn’t taken the role? Let us know in the comments!