Last updated on: October 30, 2025

Here’s the thing about Mark Harmon: he’s not just another actor who happened to land a good role. He’s the guy who quietly built one of the most respected careers in television. Think about it—how many actors can say they’ve headlined a global hit for nearly two decades and still have people raving about roles they played back in the ’80s? Not many.

If you’ve ever flipped channels and stumbled upon NCIS, chances are you know exactly who Leroy Jethro Gibbs is. Stern. Mysterious. A man of rules—but also heart. That was Harmon. And while NCIS is definitely his crown jewel, the truth is, his story stretches way further. He’s been the steady heartbeat in legal dramas, medical shows, and even one of the greatest political dramas ever made.

So today, I’m walking you through the five best Mark Harmon TV shows, ranked by IMDb ratings and popularity. But not just with numbers—we’re going to talk about why these shows mattered, how they shaped his career, and why they still hold up today.

Who is Mark Harmon?

Picture this: it’s the 1970s, and Mark Harmon is the golden boy at UCLA. Star quarterback. Son of football legend Tom Harmon and actress Elyse Knox. Everyone assumes he’ll go pro. But life had other plans.

Harmon traded touchdowns for scripts. Instead of stadium crowds, he stepped into the unpredictable world of Hollywood. At first, it was bit parts—guest appearances on shows like Police Woman—but soon he found himself in roles that demanded more. And he delivered.

By the time the 1980s rolled around, Harmon had his big break in St. Elsewhere. It wasn’t just another hospital show. It was the medical drama of its time. And it put him on the map. From there, he became known as a man who could handle serious, layered roles. Emmy nominations followed. Critical praise. And eventually, the role that would define him forever: Gibbs in NCIS.

When you look back, Harmon’s career feels like a steady climb. No flash-in-the-pan fame. Just slow, consistent growth, and a knack for picking the right projects.

How We Ranked the Shows

Before diving into the list, let me share how I put this together. IMDb ratings matter, but so do votes. A show with 10,000 votes and a 7.5 rating isn’t the same as one with 170,000 votes and the same score. That tells you how far-reaching a series really was.

Of course, numbers only tell half the story. Some older shows never racked up big vote counts because IMDb didn’t exist when they aired. So I also factored in cultural impact, critical acclaim, and how important each role was to Harmon’s journey.

Think of this as a mix of hard data and a little common sense.

Top 5 Mark Harmon TV Shows

1. NCIS (2003–2021)

Let’s be honest—you knew this one was coming. With a 7.8 rating on IMDb and more than 172,000 votes, NCIS is not just Mark Harmon’s most famous role. It’s a television phenomenon.

Here’s what made Gibbs special: he wasn’t your typical TV lead. Gibbs wasn’t overly chatty or flashy. He was quiet. A bit haunted. But he commanded respect in every scene. Harmon nailed the balance between hard-nosed leader and wounded soul, and fans connected with that.

I remember the first time Gibbs gave one of his “rules.” Simple, direct, but with so much weight. Those rules became part of the show’s DNA—and part of TV culture.

For nearly 20 years, Harmon carried NCIS. It became one of the most-watched shows in the world, spun off into multiple series, and turned Harmon into one of the highest-paid actors on television. Even after he stepped away, the shadow of Gibbs still looms large.

2. St. Elsewhere (1982–1988)

Before Gibbs, there was Dr. Robert Caldwell. St. Elsewhere wasn’t just another hospital drama—it was the show that set the standard for all the ones that followed. It won 13 Emmys, pushed boundaries, and wasn’t afraid to dive into tough topics.

Harmon’s character, Caldwell, was groundbreaking. He was one of the first TV characters to deal directly with the AIDS epidemic at a time when most shows wouldn’t touch the subject. That storyline wasn’t just bold—it was necessary. And it showed Harmon could carry weighty, emotional arcs without blinking.

Even though St. Elsewhere doesn’t have the same IMDb vote numbers as NCIS (it’s an older series, after all), its legacy is undeniable. Many critics still rank it among the greatest TV dramas ever. For Harmon, it was proof he wasn’t just a pretty face or “the football guy.” He was a serious actor.

3. Reasonable Doubts (1991–1993)

Now here’s a hidden gem. With an IMDb rating of 7.4 and about 10,500 votes, Reasonable Doubts doesn’t get talked about enough.

Harmon played Detective Dicky Cobb, who teams up with a district attorney who happens to be deaf, played by Marlee Matlin. Their partnership was unique, not just because of the crime stories, but because the show tackled communication and accessibility in ways TV hadn’t really explored before.

The chemistry between Harmon and Matlin was electric. You felt their bond, their frustrations, their trust. Even though the series only ran two seasons, it made a lasting impression.

If you’re ever looking for something different from Harmon’s career, this is the one I’d recommend. It’s like finding a secret track on an album—less famous, but just as good.

4. Chicago Hope (1996–2000)

By the mid-’90s, medical dramas were everywhere, thanks to ER. But Chicago Hope carved its own space, and Harmon was a big part of that. He joined as Dr. Jack McNeil, a surgeon with both skill and heart.

The show racked up 42 Emmy nominations and 7 wins, which tells you just how respected it was. Harmon’s character brought a grounded, empathetic touch to a series often filled with high-stakes medical crises. He wasn’t just the guy in the white coat—he was the one you rooted for.

While Chicago Hope didn’t reach the cultural dominance of ER, it still mattered. For Harmon, it showed once again that he could hold his own in a competitive landscape. Another notch on a career that kept climbing higher.

5. The West Wing (2002)

This one was short but unforgettable. Harmon appeared in just four episodes of The West Wing, playing Secret Service Agent Simon Donovan. His job? Protecting C.J. Cregg, played by Allison Janney.

In those few episodes, Harmon made such an impact that he earned an Emmy nomination for Outstanding Guest Actor. Think about that—four episodes, and he stood out among one of the best casts in TV history.

Donovan’s story ended tragically, but fans still remember him. And fun fact: producers later said Harmon’s performance here convinced them to cast him as Gibbs in NCIS. Without The West Wing, we might not have gotten NCIS the way we know it.

Honorable Mentions

Of course, there’s more. Harmon’s early series 240-Robert gave him action-star cred. His guest arc on JAG introduced Gibbs and served as the backdoor pilot for NCIS. And let’s not forget the made-for-TV movies where he experimented with different roles, proving his range beyond just dramas.

Why Mark Harmon’s TV Legacy Stands Out

So what makes Harmon’s career so special? Simple: consistency.

He’s been a part of major shows in the ’80s, ’90s, 2000s, and beyond. Very few actors manage that. His characters—whether doctors, detectives, or federal agents—share qualities people admire: intelligence, integrity, quiet strength.

Behind the scenes, Harmon also shaped NCIS as an executive producer, guiding its tone and direction. He wasn’t just showing up to act—he was building something that lasted.

When you think of TV icons, you think of people like James Gandolfini in The Sopranos or Kiefer Sutherland in 24. Harmon belongs in that conversation. He may not have been the flashiest star, but he was the kind that stuck. Reliable. Believable. Always compelling.

Conclusion

Looking back, it’s clear that Mark Harmon’s career isn’t defined by just one role—it’s a collection of them. From the groundbreaking realism of St. Elsewhere to the global phenomenon of NCIS, his top five shows—rounded out by Reasonable Doubts, Chicago Hope, and The West Wing—paint a picture of an actor who understood the power of storytelling on television.

If there’s one takeaway, it’s this: Mark Harmon built his legacy not with loud performances, but with steady, authentic ones. The kind that sneak up on you and stay with you long after the credits roll.

And maybe that’s why, even now, when you think about the greatest TV actors of all time, his name just feels right at the top.