The 42-year-old actor will play Bob Waite, the community college's politically savvy head custodian. In the episode, Annie (Alison Brie) and her criminology professor Buzz Hickey (guest star Jonathan Banks of "Breaking Bad") have to contend with the shrewd Bob as they team up to navigate Greendale’s corridors of power.
View slideshow: Guest stars for Season 5 of NBC's "Community"
Fillion is a fan of "Community" who visited the set last year, and posted a photo on WhoSay with cast members Yvette Nicole Brown, Joel McHale and Jim Rash with the caption, “It’s my #community dream come true!”
Fillion's guest appearance marks his first return to comedy since his days on ABC's "Two Guys and a Girl." His other TV credits include "Buffy the Vampire Slayer," "Firefly" and "Desperate Housewives." He currently stars as mystery novelist Richard Castle on ABC's "Castle," which airs Mondays at 10/9 p.m. CT.
NBC has not yet announced a premiere date for Season 5 of "Community." Fillion’s episode is slated to air midway through the new season.