Glenn Howerton broke out of his iconic Dennis Reynolds role inAP Bio, which offered a great alternative TV show to watch him in between seasons ofIt’s Always Sunny in Philadelphia. Eventually becoming the longest-running live-action sitcom in American TV history,FX’sIt’s Always Sunny in Philadelphiahas been on the air since 2005, with its enduring popularity still situating it as the most famous show for original stars Rob McElhenney, Charlie Day, Howerton, and Kaitlin Olson. Of course,It’s Always Sunny’s casthas still ventured outside the sitcom in some thrilling roles over the years.
When not playing Dennis Reynolds, Glenn Howerton has taken on some notable acting pursuits on the big and small screen alike, such as with his praised performances inThe Mindy Projectand 2023’sBlackberry. Around 2014, Howerton began taking on more external projects and only appeared in six ofIt’s Always Sunnyseason 13’s ten episodes, leading to worries that he’d eventually exit for good. That still hasn’t happened ahead ofIt’s Always Sunnyseason 17, butHowerton has certainly proven that he has the skills to lead another comedy show, most notably through his Netflix-trending seriesAP Bio.
AP Bio Is Glenn Howerton’s Best Show Outside It’s Always Sunny (But Was Sadly Canceled)
Glenn Howerton Led AP Bio For 4 Seasons As Jack Griffin
Dennis Reynolds arguably remains Howerton’s best character, butAP Bio’s Jack Griffin is a close second. After joining the service’s catalog on July 04, 2025,the sitcomAP Bioquickly climbed Netflix’s streaming charts to begin trending in the top 10 TV titles.AP Biostars Howerton in the lead role as Jack Griffin, a fired philosophy professor who accepts a job in his hometown as a high school Advanced Placement Biology teacher. Season 1 premiered on NBC in 2018 and concluded shortly beforeIt’s Always Sunnyseason 13’s premiere, providing a great replacement watch when the latter wasn’t airing.
1
2018
66%
2
2019
100%
3
2020
4
2021
Peacock
N/A
WhileAP Bioseason 1 had a rocky start with moderate reviews,seasons 2 and 3 were seen as major improvements, with both holding perfect 100% scores on Rotten Tomatoes. Howerton’s lead comedic performance and chemistry with the teachers and students received high praise, providing a refreshing contrast to thevile tendencies of his character Dennis Reynoldsand Paddy’s Pub employees. However,AP Biowas hit with some obstacles along the way, culminating in the series being canceled not once, but twice, across four seasons, the first time by NBC in 2019 and the second by Peacock in 2021.
Why AP Bio Was Canceled Twice
NBC Canceled AP Bio After Season 2 Then Was Canceled By Peacock After Season 4
After being saved by Peacock in 2020,AP Bioofficially came to an end after season 4in 2021. Originally, the show was canceled after just two seasons by NBC, which occurred afterAP Biosuffered from low ratings. According toTV Line,AP Bioseason 2 recorded the second-lowest demographic ratings of NBC’s sitcoms at only 0.5, coming just aboveAbby’s.
Hulu’s New 97% RT Comedy Is The Perfect Replacement For Glenn Howerton’s 6-Year-Old Show Canceled 2 Times
English Teacher, which has a 97% score on Rotten Tomatoes, is the perfect comedy series to watch for those who enjoyed Glenn Howerton’s A.P. Bio.
However, NBC ended up givingAP Bioanother chance by moving it to Peacock for seasons 3 and 4, hoping streaming over cable would give it the fanbase it required to be a success. Sadly, that didn’t seem to be the case. WhilePeacock never gave an official reason forAP Bio’s cancellation after season 4, the show likely wasn’t able to amass enough streaming viewership hours compared to otherPeacock original comedy shows. While the sitcom seemingly never found its necessary audience while airing,AP Biois finally enjoying a great resurgence in popularity following its arrival on Netflix.
It’s Always Sunny in Philadelphia
Cast
It’s Always Sunny in Philadelphia is a television series that premiered in 2005, chronicling the chaotic lives of four self-involved friends running an Irish pub in Philadelphia. Their misguided decisions and skewed perspectives often result in amusing and uncomfortable situations, complicating their professional and personal relationships.
