After much anticipation, the unlikely meeting of the two worlds unfolded on Wednesday's installment of "Abbott Elementary."

The two sitcoms could hardly be more tonally different, but this week’s crossover episode of “Abbott” was relatively seamless.

Charlie learns to read, Dee impersonates Ben Franklin, and Frank fights raccoons. We don't quite know what's up with Dennis though.

Philly pride runs strong, even for celebrities. The Welcome to Wrexham creator and Bradley Cooper are not the only famous guest stars to pay tribute to their roots in an episode of Abbott. Eagles football players Jalen Hurts and Jason Kelce also made cameos in Season 3, as Abbott ’s always one to cater to their PA fanbase.

With the first part of 'Abbott Elementary' and 'It's Always Sunny in Philadelphia's crossover airing Wednesday on ABC, Kaitlin Olson has some tips.

Two comedy forces collided this week on Abbott Elementary, as the school staff welcomed the Paddy’s Pub gang from FXX’s It’s Always Sunny in Philadelphia. Did the crossover episode make the grade, though?

Here's a look at our real-time thoughts on tonight's crossover between FXX's It's Always Sunny in Philadelphia and ABC's Abbott Elementary.

The "It's Always Sunny in Philadelphia" crew is headed to "Abbott Elementary" in the first of two crossover episodes. The highly anticipated crossover episode will see Charlie (Charlie Day), Mac (Rob McElhenney),

The collaboration commences with Season 4, Episode 9, of "Abbott Elementary," airing Jan. 8, and will continue with a follow-up episode of "It's Always Sunny in Philadelphia," expected to air in the show's upcoming Season 17.

Stream the It's Always Sunny in Philadelphia and Abbott Elementary crossover episode on platforms like Hulu, DirecTV Stream, Fubo TV, and Sling TV.

This week's "Abbott Elementary" episode is just half of the story. "Volunteers" featured the long-awaited crossover with FX's long-running "It's Always Sunny in Philadelphia," as told from the vantage point of the hit ABC sitcom.