The 15 Longest-Running Shows On American TV

Television is arguably the most familiar, comforting medium available. It sits in our home, an intimate and essential part of most housing plans. Its offerings are accessible with the click of a button, whether on terrestrial television, basic cable packages, premium cable, or, more often in our modern times, binged over the Internet in one sitting. And its stories (usually) continue over an extended period, giving us ample time to become accustomed to and fall in love with the characters and narratives.

In celebration of TV’s ability to comfort, we’ve compiled a list of the 15 longest-running shows on American television. A few caveats: We’ve limited the survey to scripted, narrative shows, eschewing long-running news, sports, and variety programs. We’ve also chosen to eliminate soap operas, a few of which have been airing in daytime slots for more than 50 years.

What remains is an intriguing and elucidating snapshot of what America returns to, time and time again, for comfort. Ready to tune in?

Running 15 seasons from 2000 through 2015, “CSI: Crime Scene Investigation” was a game-changer for CBS, a procedural that rivaled “Law & Order” for ubiquity and relevance.

The show, created by Anthony E. Zuiker, emphasized the importance of forensic evidence in criminal justice, bringing the now-commonplace ideas of DNA or blood splatter to the forefront of culture. It originally starred Michael Mann muse William Petersen as Dr. Gil Grissom, a smart but withdrawn forensic analyst who leads a team in solving some of the most puzzling or difficult crimes in Las Vegas, Nevada.

Petersen left the show in Season 9, leaving room for other leading actors to shoulder the focus, including Marg Helgenberger (“China Beach”), Laurence Fishburne (“Hannibal”), Ted Danson (“The Good Place”), and Elisabeth Shue (“The Boys”). The phenomenon of “CSI” inspired a litany of spinoffs, including “CSI: NY,” “CSI: Cyber,” the memeable “CSI: Miami,” and “CSI: Vegas,” the recently canceled sequel to the original series.

Who lives in a pineapple under the sea? “SpongeBob SquarePants,” and he’s been getting into misadventures in Bikini Bottom for 16 seasons and counting.

The versatile Tom Kenny stars as the title character on the Nickelodeon juggernaut. SpongeBob is bright, curious, optimistic, very loud, and often a little mischievous. His life under the sea includes hanging out with his dimwitted best friend Patrick (Bill Fagerbakke), working at the Krusty Krab fast food restaurant run by Mr. Krabs (Clancy Brown), and annoying his crotchety next-door neighbor, Squidward (Rodger Bumpass).

There are many tentacles that fan out from the “SpongeBob SquarePants” octopus, including a series of motion pictures (with “The SpongeBob Movie: Search for SquarePants” coming to theaters Christmas 2025), a couple of spinoff shows (Patrick hosts a talk show now!), various video games, and perhaps most surprisingly, a critically acclaimed Broadway musical that received 12 Tony nominations.

“It’s Always Sunny in Philadelphia” has been on the air for 17 seasons and shows no signs of slowing down as the longest-running live-action sitcom on television. Debuting in 2005 on FX, the comedy traffics in selfishness, terrible behavior, and yelling over petty concerns; think “Seinfeld” cranked to an 11. The gang of sociopaths includes twins Dennis and Dee Reynolds (Glenn Howerton and Kaitlin Olson), their father Frank (Danny DeVito), the vain and insecure Mac (Rob Mac), and the self-proclaimed “wild card” Charlie Kelly (Charlie Day).

The series dives headfirst into many social taboos (the pilot is literally called “The Gang Gets Racist”), but tends to do so with a level of self-awareness and even intelligence. In fact, in its most recent seasons, the show has metatextually dug into its problematic past to figure out where it can go from here while staying relevant (and funny). As a result, “Always Sunny” is releasing some of its strongest episodes yet.

“Criminal Minds” aired from 2005 to 2020 for 15 seasons, before getting revived as “Criminal Minds: Evolution” on Paramount+ in 2022. The CBS procedural has now been on for 18 seasons, with a 19th on the way.

Whereas “CSI” dove into the physical for its unique spin on the crime genre, “Criminal Minds” examines the psychological motivations behind wrongdoers — the “criminal minds,” if you will. It began as a vehicle for Mandy Patinkin, who played expert criminal profiler Jason Gideon before leaving after Season 2. It was a bit of an acrimonious split, with Patinkin telling New York Magazine, “The biggest public mistake I ever made was that I chose to do ‘Criminal Minds’ in the first place … It was very destructive to my soul and my personality.”

After Patinkin’s exit, other leading players included Thomas Gibson (“Chicago Hope”), Shemar Moore (“S.W.A.T.”), Paget Brewster (“Community”), and Joe Mantegna (“The Simpsons”).

What if a dog were really smart, brave, and helpful? That’s the irresistible premise behind “Lassie,” a show that ran for 19 seasons from 1954 to 1973, starting on CBS before moving to syndication. Throughout the show’s run, many cast members came and went, but one character remained steady: Lassie herself, a gorgeous Rough Collie that got into adventures and readily saved her companions (though there were several dog actors who played Lassie over the series).

For the first three seasons, Lassie lived on a farm as the ally of young boy Jeff Miller (Tommy Rettig). From Seasons 4 through 10, an orphan boy named Timmy (Jon Provost) was introduced, giving Lassie a new little kid to save. From Seasons 11 through 16, Lassie was adopted by Forest Ranger Corey Stuart (Robert Bray) and went on more open adventures with him. Season 17 functioned basically as an anthology, with Lassie going on a self-contained adventure in each episode.

And finally, for the last two seasons, Lassie was taken into a ranch that housed orphans run by Garth Holden (Ron Hayes).

Starting as a wildly successful radio program in 1952, the Western series “Gunsmoke” was adapted for CBS television in 1955, running for 20 seasons until 1975 (and, amazingly, it debuted on Nielsen’s acquired top 10 in 2025).

Taking place in the aftermath of the Civil War, the show starred James Arness as U.S. Marshal Matt Dillon, following his efforts to maintain law and order in the town of Dodge City, Kansas. Other notable characters included the physician Doc Adams (Milburn Stone), the saloon owner Kitty Russell (Amanda Blake), and a pair of bumbling deputies in Chester B. Goode (Dennis Weaver) and Festus Haggen (Ken Curtis).

After the 1975 finale, five made-for-TV movies were produced through the 1980s and ’90s, all featuring Arness in the leading role as Dillon. The most notable of these titles is 1987’s “Gunsmoke: Return to Dodge,” which places Marshal Dillon as the victor of a life-or-death gun battle, but at the cost of staying in Dodge City — or finally rekindling his will-they-won’t-they relationship with Kitty (Blake, returning once more).

When “American Dad!” premiered on Fox in 2005, it was explicitly a topical and satirical series. American culture was forever reshaped by the presidency of neo-conservative George W. Bush, and co-creators Seth MacFarlane, Mike Barker, and Matt Weitzman — all three of whom worked on “Family Guy” — crafted “American Dad!” as a commentary on thriving within that culture.

Twenty-one seasons later, “American Dad!” is still cooking, moving back to Fox after living on TBS for a while. And while its topical sting is perhaps less potent (though the presidency of Donald Trump certainly keeps some of its satire relevant), it still maintains healthy laughter from its relationships and absurdities.

MacFarlane stars as Stan Smith, a jingoistic CIA agent who’s just trying to live the American Dream. His family includes a voice-of-reason wife, Francine (Wendy Schaal), a nerdy son, Steve (Scott Grimes), a liberal daughter, Hayley (Rachael MacFarlane), a talking goldfish, Klaus (Dee Bradley Baker), and of course, a camp alien, Roger (Seth MacFarlane).

Combining gritty depictions of medical procedure with the pleasures of soapy, character-driven twists and turns, “Grey’s Anatomy” was a smash sensation for ABC in its 2005 debut, putting creator Shonda Rhimes on the map as a television magnate. It’s currently airing its 22nd season.

Ellen Pompeo stars as Dr. Meredith Grey, and she’s one of three regular cast members to have been credited in every season (the other two being Chandra Wilson as Dr. Miranda Bailey and James Pickens Jr. as Dr. Richard Webber). Dr. Grey began the show as a surgical intern, quickly getting into conflicts and romantic entanglements with her fellow colleagues; as the show has progressed, she’s climbed the professional ladder, and her relationships — namely with Patrick Dempsey’s Dr. Derek Shepherd — have also changed quite a bit. (No spoilers!)

Other notable breakthrough performers on the long-running medical drama include Katherine Heigl (“Roswell”), Sandra Oh (“Killing Eve”), and T. R. Knight (“The Good Wife”).

And now, another CBS procedural! “NCIS” stands for the Naval Criminal Investigative Service, and the show details this agency’s solving of various cases over its current 23 seasons.

A spinoff of “JAG” (which stands for Judge Advocate General’s Corps) that first aired in 2003, “NCIS” starred Mark Harmon as Supervisory Special Agent Leroy Jethro Gibbs, the no-nonsense but loving leader of the law enforcement agency. After Harmon left in Season 19, the team was taken over by Gary Cole as Supervisory Special Agent Alden Parker.

“NCIS” helped codify one of the most omnipresent tropes in televised crime media: The quirky lab tech who approaches the grisly job with surprising irreverence. Pauley Perrette indelibly personified this type for 15 seasons as the goth-tinged forensic scientist Abby Sciuto; from Season 16 to the present, this type has been played with equal comedic energy by Diona Reasonover as forensic scientist Kasie Hines.

And now, another Seth MacFarlane Fox animated sitcom!

The theme song for “Family Guy” begins with its two main characters complaining that “all we see is violence in movies and sex on TV.” And yet, for its 23-season run (with Season 24 coming), “Family Guy” has given us nothing but violence, sex, and all manner of controversial topics mined for laughs.

MacFarlane stars as Peter Griffin, our dim-witted “Family Guy” who bumbles his way through his patriarchal duties alongside his severe wife, Lois (Alex Borstein), his nerdy son, Chris (Seth Green), his put-upon daughter, Meg (Mila Kunis), his devilish infant son, Stewie (MacFarlane), and his talking dog, Brian (MacFarlane).

“Family Guy” will do pretty much anything for the sake of a joke, often breaking the fourth wall or, more famously, cutting away to a one-off visual joke that is unrelated to the narrative. Critics may argue that “Family Guy” is, thus, a formulaic and lazy joke machine. But for fans of hard jokes delivered at a brisk pace, there’s nothing like it.

TV producer Dick Wolf changed the television landscape forever with his iconic NBC crime procedural “Law & Order.” Originally airing from 1990 through 2010, then receiving a revival in 2022, “Law & Order” is essentially two procedurals in one. Each episode of its 25 seasons (thus far) starts as a police procedural, showing New York detectives solving a vicious criminal case. Then, when a suspect has been pegged, it switches into a legal procedural, putting the fate in the hands of the district attorneys.

There are countless iconic performers throughout the series’ run, including Jerry Orbach (“Beauty and the Beast”), Jesse L. Martin (“The Irrational”), Benjamin Bratt (“Andor”), S. Epatha Merkerson (“Chicago Med”), and the inimitable Sam Waterston (“Grace and Frankie”).

The show is also notable for giving early gigs to many New York-based actors, especially those known for the stage or those about to break out, making rerun marathons of “Law & Order” a “Where’s Waldo?” for fans of the performing arts.

Is there a bigger television crime than a spinoff eclipsing its antecedent?

We can argue until we’re blue in the face about which “Law & Order” has more cultural impact, but the cold, hard facts cannot be refuted: “Special Victims Unit,” the spinoff that focuses on heinous crimes of a sexual nature, has run for 27 seasons, beating the OG “L&O” by two seasons.

The show, which debuted on NBC in 1999, stars Mariska Hargitay as Olivia Benson, arguably the single most successful law enforcement agent in the history of the world. Throughout these 27 seasons, Benson gets promoted from junior detective all the way to captain, dealing with personal issues and growth as she busts the worst criminals you can imagine.

Other familiar faces from the series’ run include Christopher Meloni as the fiery detective Elliot Stabler, Ice-T as the nonplussed Fin Tutuola, and the late Richard Belzer as the sarcastic John Munch.

“South Park” began its Comedy Central life in 1997. It was a crudely animated and boundary-pushing comedy of vulgarity starring its creators, Trey Parker and Matt Stone, as a group of elementary school friends in a small Colorado town.

It’s been 28 seasons since that basic cable debut, and “South Park” has become an empire, a countercultural force that relentlessly makes fun of any piece of mainstream culture that comes into its purview. It’s rare for any comedy to feel “dangerous,” let alone over 28 years, but “South Park” continues to pull off that feat by any means necessary, fearlessly parodying the Trump administration despite the backlash.

Parker plays Stan Marsh, our everyman, and Eric Cartman, a kid whose personality runs the gamut from “bigoted” to “murderous sociopath.” Stone plays Kyle Broflovski, the most emotionally intelligent of the group, and Kenny McCormick, whose voice is always muffled and who often died in early episodes, coming back to life inexplicably in the following installment.

For millennials of a certain age, there is no childhood experience like the “Power Rangers.” Adapted from the Japanese show “Kyōryū Sentai Zyuranger,” the action-adventure series debuted in 1993 on Fox Kids, introducing a wide range of viewers to the pleasures of martial arts and kaiju genres. “Power Rangers” evolved over 30 seasons, each one receiving some kind of season-long gimmick — from “Mighty Morphin Power Rangers” to “Power Rangers Dino Thunder” and finally “Power Rangers Cosmic Fury” — while maintaining a throughline of continuity.

At its core, “Power Rangers” presents a crew of teenagers who are excellent at martial arts, earn color-coded suits, and control a series of mechanized robot animals that can merge together to become a “Megazord.” Villains over the years include Rita Repulsa, Lord Zedd, and the delightful Putties, anonymously gray henchmen who were easily dispatched by the Mighty Morphin Power Rangers.

And if none of this makes sense to you, well, you’ve got 30 seasons worth of lore to catch up on before a potential Disney+ revival. I’d start soon.

Here it is, the granddaddy of all scripted, narrative-driven American TV shows. “The Simpsons,” which began life as a 1989 spinoff of short segments from “The Tracey Ullman Show,” put the Fox network on the map, emboldened what was possible with the television sitcom form, and became an unstoppable cultural juggernaut. It’s been on the air for 37 seasons, and it doesn’t seem like it will stop anytime soon.

“The Simpsons” follows a typical suburban family through their dysfunctional trials and tribulations in the town of Springfield. Homer Simpson (voiced by Dan Castellaneta) is the idiotic father, Marge (Julie Kavner) is the put-upon mother, Bart (Nancy Cartwright) is the rebellious son, Lisa (Yeardley Smith) is the intelligent daughter, and Maggie is the pacifier-sucking baby (voiced notably by Elizabeth Taylor in a Season 4 episode).

To be a “Simpsons” fan is to argue over its golden age, its best showrunner, its tonal shifts, and its seeming lack of contemporary quality. But any “Simpsons” fan has been irrevocably changed by the wide-ranging comedy. It’s the longest-running primetime show of all time for a reason.