The Abbott Elementary & It's Always Sunny In Philadelphia crossover was a hit, but Glenn Howerton’s Dennis was mysteriously evasive for most of it.

The cast of "It's Always Sunny in Philadelphia" will appeared on "Abbott Elementary." Here's how to watch, when it airs and what to know about the crossover.

ABC released a huge new image gallery from the crossover event between FXX's It's Always Sunny in Philadelphia and ABC's Abbott Elementary.

TV schedule really started off perfectly with a hilarious crossover of Abbott Elementary and It’s Always Sunny in ...

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, ...

The crossover episode of two is the ultimate tribute to the city’s attitude, quirks, and, of course, its signature phrase: ...

Mark your calendars! A super exciting crossover between two of your favorite shows, ‘Abbott Elementary’ and ‘It’s Always Sunny in Philadelphia,’ is happening this coming January 8th on ABC at 8:30 PM ...

The Abbott Elementary and It’s Always Sunny episode titled "Volunteers" will see the Always Sunny characters brought in as volunteers to “help” the Abbott staff. It seems the whole Paddy’s crew — Rob ...

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

Plus, the star reveals he auditioned many times for 'It's Always Sunny in Philadelphia' before landing his role as 'Abbott's ...