Between Frank's strange lines and Charlie's hilarious speeches, the It's Always Sunny gang left fans with a lot of hilarious ...

Here's some background and inside jokes to help fill in some of the gaps for viewers who don't watch both Philly-based shows.

The highly anticipated crossover episode of “Abbott Elementary” and “It’s Always Sunny in Philadelphia” blends the raunchy, ...

Charlie, Mac, Dee, Dennis and Frank will cross paths with Janine, Ava, Barbara, Gregory, Melissa, Jacob and Mr. Johnson The ...

Philly pride runs strong, even for celebrities. The Welcome to Wrexham creator and Bradley Cooper are not the only famous ...

The highly anticipated crossover episode between Abbott Elementary and It's Always Sunny in Philadelphia is almost here and PEOPLE has the exclusive first look! The episode, titled "Volunteers ...

The trailer for the crossover episode between Abbott Elementary and It’s Always Sunny In Philadelphia has been released – check it out below. The one-off show will air on ABC – the home ...

"Abbott Elementary" returns to class with the highly anticipated crossover episode with FXX's "It's Always Sunny in Philadelphia" on January 8. ABC recently released a new promo for the episode ...

The worlds of "Abbott Elementary" and "It's Always Sunny in Philadelphia" collide next week — and from the looks of the first teaser, it'll be a (predictably) messy meeting. ABC released a look ...