The 30 Most Iconic TV Crossover Episodes of All Time

To call a TV crossover episode a gimmick is accurate but it's not an insult. For decades, TV shows have gotten audiences excited by smashing together two (or more!) different series in a crossover episode or arc.

Some crossovers are major events, orchestrated by the network to draw attention (and extra eyeballs) to a slate of programming. Other times the crossovers are meta jokes that come to life when characters from one show make their way into another. (The crossover characters don't need to be a natural fit—indeed, sometimes the best crossovers consist of two shows you'd assume have nothing in common.) Sometimes the crossovers make sense because the various series are all related—think some of the long-running police or legal procedurals and their various city-specific spin-offs, or the Star Wars and Marvel series on Disney+. Those Disney+ shows are so innately connected that it almost doesn't feel fair to call them "crossovers," so you won't find them on this list. But for 30 of most iconic TV crossover episodes of all time, read on.

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We tend to think of crossovers as a more modern TV phenomenon—or at least one that was big in the '90s—but there were crossovers back in the '50s, too. One notable, fairly meta one happened in Season 6 of I Love Lucy, when Lucy Ricardo (Lucille Ball) becomes determined that Superman, who's making appearances at Macy's in New York City, will come to Little Ricky's birthday party. Adventures of Superman star George Reeves appears as the character he was famous for playing on TV, though his real name isn't uttered throughout the episode.

Another masked crime-fighting duo of the era showed up on the '60s Batman series on two occasions: First, the Green Hornet (Van Williams) and his sidekick Kato (Bruce Lee) make a cameo appearance in Season 2 when they pop their heads out of a window as Batman (Adam West) and Robin (Burt Ward) scale a wall. Later in the same season, they enjoy a proper crossover when they properly team up with the dynamic duo to take down a mutual foe in a two-episode adventure.

These two iconic Hanna-Barbera series were already basically the same (one family was in the past, the other in the future), but it wasn't until 1987 that the two '60s cartoons finally crossed over in The Jetsons Meet the Flintstones, a two-hour TV special. The event has the Jetsons and the Flintstones (and the Rubbles) switching places after a time-travel experiment.

Steve Urkel (Jaleel White), the breakout character from Family Matters, made his way to San Francisco to visit the Tanners in this 1991 crossover between two of ABC's biggest sitcoms. Uncle Jesse (John Stamos) attempts to teach the infamously nerdy Urkel how to be cool, and Urkel helps cheer up Stephanie (Jodie Sweetin) about having to wear glasses.

The finale of The Fresh Prince of Bel-Air featured surprise cameos from the stars of two other iconic Black sitcoms. When the Bel-Air mansion that Will (Will Smith) has called home goes up for sale, the potential buyers include the gang from Diff'rent Strokes (Conrad Bain, Gary Coleman) and the crew from The Jeffersons (Sherman Hemsley, Isabel Sanford, and Marla Gibbs).ae0fcc31ae342fd3a1346ebb1f342fcb

The NBC sitcom Mad About You basically created a shared sitcom universe, beginning in Season 1, when Paul Buchman (Paul Reiser) runs into Seinfeld's Cosmo Kramer (Michael Richards), who is revealed to have been subletting Paul's old apartment. Then, things got even more connected when Lisa Kudrow, who had played a waitress named Ursula on Mad About You, was cast on Friends. The existence of both of their characters in this universe was explained when it was revealed that Ursula was Phoebe's twin sister.

In 1994, this connected universe was the basis of a big stunt NBC called "Blackout Thursday," where a power outage caused by Mad About You's Jamie Buchman (Helen Hunt) impacts the rest of the NBC Thursday night lineup, other than Seinfeld.

"A Star Is Burns," a 1995 episode of The Simpsons, brought Jay Sherman (Jon Lovitz), the main character of The Critic to Springfield to judge a film festival. The Critic was created by two Simpsons alums, and the shows shared an executive producer, making this seem like a friendly bit of cross-promotion. However, The Simpsons creator Matt Groening really disliked the crossover, going so far as to take his name off the episode. To quote Jay, he might have said, "It stinks!," but the episode itself is actually quite funny.

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Your friendly neighborhood Spider-Man swings over to Professor Charles Xavier's mansion for this two-part 1995 crossover between Spider-Man: The Animated Series and X-Men: The Animated Series. Such crossovers were commonplace in the pages of the Marvel comics that the superheroes come from, but it was still more novel on TV at this time. Of course, the development of the Marvel Cinematic Universe would present many of team-ups and crossovers just a couple of decades later.

In the 1997 episode "The Springfield Files," Special Agents Mulder and Scully (voiced by X-Files stars David Duchovny and Gillian Anderson) come to Springfield to investigate an alien sighting—revealed to be Mr. Burns hopped up on a bunch of medical treatments. As fun as it is to see Homer interact with the sci-fi characters, "The Springfield Files" is also notable for the presence of another guest star: Star Trek's Leonard Nimoy.

Before Justice League, there was "World's Finest," a three-episode event in 1997 that revolves around Superman and Batman's first meeting. Batman: The Animated Series had ended its initial run two years prior with only fleeting allusions to the Man of Steel's existence, but "World's Finest" has them interact for real when the Dark Knight heads to Metropolis in pursuit of the Joker.

In 1998, Power Rangers villain Astronema kidnaps and brainwashes the otherwise very cool dudes from the live-action series Ninja Turtles: The Next Mutation and forces them to fight the other show's titular heroes. As you might expect the Turtles break free of their brainwashing and end up teaming up with the Rangers to beat the bad guys.

Buffy and its spinoff Angel crossed back over a number of times, but no instance was more heartbreaking than the 1999 Angel episode, "I Will Remember You." When Angel (David Boreanaz) becomes a human, he and Buffy (Sarah Michelle Gellar) finally get a chance to be together, but the former realizes that he needs to to turn back time and erase the wonderful events of the night in order to save her life.

The Season 7 X-Files episode "X-Cops" is one of the more clever and unexpected crossovers in TV history. The whole hour is shot as though it's an episode of the Fox reality show Cops, except here, Mulder and Scully are on the force chasing after not a regular perp, but a supernatural entity.

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Over three specials in the mid-'00s, the Nickelodeon series The Adventures of Jimmy Neutron, Boy Genius and The Fairly OddParents all came together. Notably, when Jimmy came to The Fairly OddParents universe, he was traditionally animated to match the style of that show, and when Timmy went over to Jimmy Neutron, he was animated via CGI, in keeping with that series' aesthetic.

Not to be outdone by Nickelodeon, Disney Channel aired its own three-way crossover special in 2006, bringing That's So Raven, The Suite Life of Zack & Cody, and Hannah Montana together. Miley Stewart (Miley Cyrus) stays at the Tipton, Raven (Raven-Symoné) has a vision about Cody (Cole Sprouse), and London (Brenda Song) wears one of Raven's designs. It's a smorgasbord of '00s tween pop culture.

Ray Langston (Laurence Fishburne) of the flagship CSI series travels to Miami and New York City for this 2009 crossover that has him leading an attempt to take down a human trafficking ring. CSI had done smaller crossovers before, but "CSI: Trilogy," which involved all three shows at the time, was big, big deal.

Two of Nickelodeon's biggest shows of the early '10s, iCarly and Victorious, meet in iParty With Victorious, a 90-minute TV movie. The plot has Miranda Cosgrove's Carly realize that her boyfriend is also seeing singer Tori Vega (Victoria Justice). Three more crossovers would air, followed by the spinoff sitcom Sam & Cat, starred supporting characters from both series.

The NBC sitcom Community is famous for its genre parody episodes and meta humor, but its greatest joke might have happened on another show. In a Season 2 episode of Community, Danny Pudi's Abed tells a story about how he was a background extra on an episode of the comedy Cougar Town but… soiled his pants. In Cougar Town's Season 2 finale, which aired a few months after that Community episode, Pudi actually appears in a scene behind Busy Philipps—until he abruptly runs off.

When Family Guy first premiered in 1999, it was criticized by some for being a crass knockoff of The Simpsons. A decade and a half later, the two marquee Fox animated comedies finally met. "The Simpsons Guy" has the Griffins visit Springfield and meet their yellow counterparts. Despite featuring the voice talents of most of The Simpsons cast, it's very much an episode of Family Guy featuring some special guests, so some of the humor might feel a little off for fans of the older series. Still, hard to deny how major (and seemingly inevitable) this crossover was at the time.

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H. Jon Benjamin provides the voice of both Archer and Bob's Burgers' title characters, and to be honest, both characters sound pretty much the same. That's the inspiration behind 2013's "Fugue and Riffs," Archer's Season 4 premiere, in which the secret agent lives with the Belcher family while he's suffering from amnesia. For this special outing, the Bob's Burgers characters are drawn in Archer's more realistic art style.

Matt Groening may have objected when The Simpsons crossed over with The Critic in 1995, but there was no controversy when it crossed over with his other show Futurama 19 years later. When the episode aired, the series finale of Futurama had already aired (it was brought back as a revival last year), making the appearance of Fry, Leela, Bender, and Professor Farmsworth in Springfield via time travel an especially welcome treat for fans.

A forensic crime-solving procedural and a pulpy supernatural drama might not initially seem like a natural crossover fit. That initial assumption isn't incorrect, yet it's because of this tonal mismatch that the 2015 crossover between Sleepy Hollow and Bones is such a welcome oddity.

Zooey Deschanel's adorkable Jess meets Andy Samberg's goofy Detective Jake Peralta in 2016's two-part Brooklyn Nine-Nine/New Girl crossover. Over the hour, the New Girl cast visits the Big Apple and crosses paths with the squad.

Two series produced by Shonda Rhimes crossed over in 2018 when Scandal's fixer extraordinaire Olivia Pope (Kerry Washington) joined forces with How to Get Away With Murder's defense attorney Annalise Keating (Viola Davis). "Allow Me to Reintroduce Myself" has the formidable pair working on a class-action lawsuit about the mass incarceration of Black Americans.

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Why did Supernatural cross over with Scooby-Doo,Where Are You! in its 13th season? The real question is: Why wouldn't it? The Winchesters get sucked into the animated mystery's universe in this 2018 outing. Once inside, a cartoon Sam (Jared Padalecki), Dean (Jensen Ackles), and Castiel (Misha Collins) must work with Mystery Inc. to stop a real ghost, rather than just some guy in a mask.

The Law & Order franchise is almost 35 years old and encompasses many shows, both past and still running, so of course, crossovers are common. The most significant for fans was the one between SVU and the premiere of Organized Crime, because it finally reunited Olivia Benson (Mariska Hargitay) with her former partner, Elliot Stabler (Christopher Meloni). Meloni left SVU after Season 12 and didn't return until 10 years later for his own spinoff.

The Chicago franchise boasts a lot of crossovers, including some with the Law & Order and FBI universes. (They're all from Dick Wolf Productions.) The "Infection" event, which had Chicago Fire, Chicago P.D., and Chicago Med all dealing with the spread of a deadly bacteria in the Windy City across three episodes in 2019, is basically an action-packed TV movie.

The CW's Arrowverse crossovers are the stuff of legend. The sixth crossover, "Crisis on Infinite Earths," borrows its title from one of the most important DC comic book storylines, and it lives up to the name, pulling five shows together for a multi-versal adventure. It's a wonder they were able to do what they did—on a TV budget, no less!

Different Naval Criminal Investigative Service teams had joined forces before, but the 2023 crossover that brings together NCIS, NCIS: Hawai'i, and NCIS: Los Angeles is the broadest, featuring a city-hopping case involving kidnapping and teamwork.

The NCIS universe has crossed over with other series, too, like when Los Angeles teamed up with Hawaii Five-0 in 2012.

Star Trek crossovers date back decades, as Spock (Leonard Nimoy) and Scotty (James Doohan) from The Original Series made appearances on The Next Generation, but those cameos pale in comparison to the 2023 episode of Strange New Worlds that brings Ensigns Mariner and Boimler from Lower Decks—an animated comedy—onto the live-action Enterprise. Lower Decks voice actors Tawny Newsome and Jack Quaid get the chance to play live-action versions in this very charming, funny crossover that went where no Star Trek crossover has gone before.