Part of what makes any TV show a success is watertight world-building that suspends our disbelief, and immerses us in the universe of its characters. Yet, some of the most successful TV shows in history have gone a step further, by sharing universes with another small-screen series.
In the case of cohesive franchises or spinoff shows, shared TV universes make a lot of sense. In fact, they often enrich the story worlds of their characters. Perhaps the most high-profile instance of this phenomenon in recent years is Taylor Sheridan’s Yellowstone shared universe, which looks set to span at least nine TV shows, including what’s in the pipeline.
But other shared TV universes can be harder to spot, because they’re less coherent fictional entities. Some prominent examples, such as the 400-show Tommy Westphall universe, are actually just fan theories based on coincidental connections. These cases won’t be included in this list, which aims to stick firmly to the facts.
Nevertheless, among the most bizarre instances of multiple TV shows purportedly sharing the same universe, several have actually been confirmed by the shows themselves. Most viewers wouldn’t know it, but in some cases the characters in two or more wildly different series belong to the same story world.
The Flintstones & The Jetsons
It was announced in October 2025 that Jim Carrey is playing George Jetson in an upcoming live-action movie adaptation of the famously futuristic cartoon family, but this adaptation will be far from the first feature-length film about The Jetsons. In fact, it’s almost 40 years since their feature-length debut, in The Jetsons Meet the Flintstones.
This animated TV movie serves as a crossover between Joseph Hanna and William Barbara’s two cartoon sitcoms from the early 1960s, The Flintstones and The Jetsons. Rather than an anomalous experiment, however, the movie revealed that the two shows’ characters exist in the same world, only during very different time periods in human history.
Detective John Munch
When Richard Belzer cameoed in The Wire, many of the show’s fans probably didn’t realize that he was playing a character with a preexisting backstory across several other TV shows, including two of the most beloved police-procedural franchises ever produced. Belzer’s Detective John Munch actually first appeared on Homicide: Life on the Street back in 1993.
He then went on to feature in multiple Homicide spinoffs, as well as Law & Order and The X-Files. By the time Munch arrived in The Wire, he’d also popped up in the sitcom Arrested Development. His final TV outing would be an anonymous 2015 cameo in Unbreakable Kimmy Schmidt.
Of all the subsections of the wider Tommy Westphall TV universe, John Munch’s collection of appearances across 22 years of television is the most verifiable. Belzer’s iconic character is unquestionably the same person every time.
Friends & Mad About You
Unbeknownst to everyone but those who watched both shows regularly, two of the biggest sitcoms of the 1990s shared the same TV universe. Friends and Mad about You are interconnected via eccentric twin sisters Phoebe and Ursula Buffay. Ursula appears in Friends eight times across its 10 seasons, while serving as a recurring character in Mad about You.
Although Phoebe never returned the favor by appearing in Ursula’s sitcom, the regularity with which we see the two sisters today in Friends demonstrates that their respective shows share the same fictional world. If Ursula doesn’t quite seem like her usual self whenever she’s in Friends, we can put it down to the two series having entirely different writing teams.
Mad Men & 30 Rock
30 Rock and Mad Men are two TV masterpieces of the 2000s that we definitely wouldn’t expect to mention in the same sentence. Yet, the shows exist together in the same TV universe, as one subtle detail of 30 Rock episode “The Moms” reveals. In this episode, Liz Lemon’s mother Margaret Lemon says she used to work at Sterling Cooper.
This employer could only be the very same New York advertising agency where Mad Men is set. What’s more, the decade in which AMC’s seminal period drama series is set matches Margaret’s story.
She worked as a secretary at Sterling Cooper immediately after graduation, in her early twenties. Given that she appears to be in her sixties in 30 Rock, which is set around four decades after the events of Mad Men, her story checks out perfectly.
Bones & Sleepy Hollow
Probably the most bizarre shared TV universe of all time encompasses both the police-procedural series Bones and the supernatural drama Sleepy Hollow. It could well be that both shows were running on empty when they attempted their unlikely crossover episodes, which most Bones fans tend to skip on rewatching the series.
Still, this shared universe is confirmed by the way Bones fully commits to making “The Resurrection in the Remains” part of its canonical story, just as Sleepy Hollow does with “Dead Men Tell No Tales”. Given that supernatural plot elements are implied elsewhere in other Bones episodes, we shouldn’t be so surprised by this revelation.
