The Teachers
Glenn Howerton as Dr. Jack Griffin
A.P. Bio is very much designed as a showcase for TV comedy heavy hitter Glenn Howerton. Prior to (and indeed concurrently with and after) his role as Jack Griffin, Howerton was best known for portraying Dennis Reynolds on long-running FX comedy It’s Always Sunny in Philadelphia. Going on two decades, Howerton’s performances as the borderline sociopathic Dennis has been a comedic masterclass. Now viewers have gotten to know him a little better via The Always Sunny Podcast and his award-winning role as Blackberry co-founder Jim Balsillie in 2023’s Blackberry.
Lyric Lewis as Stef Duncan
Stef Duncan is a history teacher at Whitlock High School and part of the unshakeable Stef-Mary-Michelle friendship trio. Playing her is Lyric Lewis, who has previously appeared in TV comedies Baskets, iCarly, and Party Down.
Mary Sohn as Mary Wagner
Mary is an art teacher at Whitlock High School and part of the aforementioned Stef-Mary-Michelle friendship trio. Playing her is Mary Sohn, a comedic actress who has appeared in Miracle Workers, Between Two Ferns: The Movie, and Curb Your Enthusiasm. She has also made several appearances voicing characters on the Comedy Bang! Bang! podcast.
Jean Villepique as Michelle Jones
Michelle Jones is the home economics teacher at Whitlock High School and is the oddball spoke of the Stef-Mary-Michelle friendship trio. Jean Villepique has popped up in numerous comedy series since 2007, including The Office, Modern Family, and Veep. Shortly before A.P. Bio, she voiced adoption caseworker Tracy in BoJack Horseman.
Patton Oswalt as Principal Ralph Durbin
Principal Ralph Durbin is the overmatched leader of Whitlock High School and the closest thing Jack Griffin has to a “friend.” Playing Durbin is the prolific comedy legend Patton Oswalt, who has been in … just, everything. In addition to his long-running career as a standup comic and actor, Oswalt is known to young audiences as the voice of Remy in Pixar’s Ratatouille.
Paula Pell as Helen Henry Demarcus
The perfectly-named Helen Henry Demarcus is Principal Durbin’s secretary who views him as something resembling her husband, son, best friend, and platonic soulmate. Playing Helen is comedic secret weapon Paula Pell. A respected writer at Saturday Night Live from 1995 through 2020, Pell has moved in front of the camera more in recent years, playing prominent roles in Parks and Recreation, Documentary Now!, and Girls5eva.
