The A-List Marvel Actor Fans Want To Star On It's Always Sunny In Philadelphia

"It's Always Sunny in Philadelphia" may be the longest-running live-action sitcom in TV history (per NPR), but it has always remained a somewhat insular production, never venturing far outside its core cast of incorrigible characters. The show has certainly pulled some big-name guest stars in the past, including Sean "Diddy" Combs and celebrated "The Shape of Water" director Guillermo Del Toro, but in general, the sitcom prefers to focus on the depraved antics of The Gang and the various bizarro characters who orbit them.

In addition to Mac (Rob McElhenney), Dee (Kaitlin Olson), Dennis (Glenn Howerton), and Charlie (Charlie Day), Danny DeVito has been the biggest name on the show, starring as the grotesque Frank Reynolds since Season 2. These five characters easily anchor most episodes of the show without any outside help, and many of the best "Always Sunny" episodes feature them alone. When an extra dose of absurdity is required, it usually arrives in the form of priest-turned-vagrant Cricket (David Hornsby) or the creepy, inbred McPoyle twins (Jimmy Simpson and Nate Mooney).

However, that doesn't stop fans of the show from wishing for their dream guest stars, especially as the show's cast has formed more connections to the broader Hollywood landscape over the years. As it turns out, there's one particular star from a beloved Marvel movie who "It's Always Sunny in Philadelphia" fans would go nuts for if they were to appear on the sitcom.

On the "It's Always Sunny in Philadelphia" subreddit, u/Snake_Plissken224 wrote, "I really want an episode where Ryan Reynolds guest stars as a love interest for Mac." 

Fans quickly rallied around the idea, with many optioning ways the "Deadpool" star might be introduced. "I think he'd make a great McPoyle relative," suggested u/mary8kw, a concept others found funny because Reynolds is conventionally attractive compared to the off-putting depictions of the McPoyle family, which have become a running gag on "It's Always Sunny in Philadelphia." Meanwhile, u/FadeToBlackSun played on that angle by suggesting Reynolds could be introduced with disdain by the other McPoyles and implying the line of dialogue: "'He's only a McPoyle by marriage. He is of tainted blood and impure filth. Look at his horrible separated eyebrows.'"

The idea of Reynolds guest starring on "It's Always Sunny in Philadelphia" isn't as far-fetched as it seems. The "Free Guy" star has become friends with Rob McElhenney in real life, and according to The Guardian, the pair purchased the Wrexham AFC football team together in 2021 under the business alias RR McReynolds, a portmanteau of the two stars' names.

Additionally, Reynolds has already been a small part of the "Always Sunny" world, though even dedicated fans may have missed it. In 2021, FX Networks released a teaser for the upcoming "Welcome to Wrexham," a docuseries chronicling the two stars' experiences buying the titular soccer club (via FX Networks on YouTube). As a gag, the teaser featured the cast of "It's Always Sunny in Philadelphia" looking at their Welsh doppelgangers in Wrexham through the Paddy's Pub TV screen before cutting to McElhenney and Reynolds, the latter of whom asks, "Did I approve a tie-in for our show and 'Always Sunny in Philadelphia'?" Overall, it seems a guest role from the star could be a real possibility.