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

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 Abbott Elementary & It's Always Sunny In Philadelphia crossover had hilarious character interactions, but it hid callbacks in its witty writing.

The star of the FX series also admits he was initially hesitant about the crossover concept as 'It's Always Sunny in Philadelphia' heads into its 17th season.

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

In the newest Abbott episode, "Volunteers," The Gang gets educated. The Abbott Elementary/It’s Always Sunny in Philadelphia Crossover Brought Out the Weirdest of Both ...

Premiering January 8, you can stream this must-watch episode with the help of services like Fubo, DirecTV Stream, Sling TV, and Hulu ...

The cast of It’s Always Sunny in Philadelphia made its way to the ABC show, which is set in Philly, for the crossover episode of comedy writers’ dreams. The brief promo for the Jan. 8 ...

This matchup brought together two Philly casts: “Abbott Elementary” and “It’s Always Sunny in Philadelphia.” The crossover ...

Claim a square if the gang speaks to the camera crew, pitches a horrible business idea or scars a student for life.

When will the It’s Always Sunny in Philadelphia episode air? While we know for a fact that the Abbott Elementary episode of the two-part crossover event will occur on January 8, the exact date ...

As of Jan. 9, the episode is available to stream on Hulu. The second crossover is expected to be an episode of "It's Always Sunny in Philadelphia," which has aired on FXX since 2013.