He appeared on numerous shows including The Tick, Popular, Charmed (3x10), Will & Grace, The New Adventures of Old Christine, Ugly Betty, Felicity, Weeds, Gilmore Girls, NYPD Blue, Desperate Housewives, The League, Space: Above and Beyond, Roswell, The Middle, Mixed-ish.
He has appeared on many of John Lehr's shows including Quick Draw, Jailbait, and TBS' 10 Items or Less, where he played main character Carl Dawson.
He had recurring roles on two Bill Lawrence's TV shows, Scrubs and Cougar Town, and appeared in cross-over between two series.
Clendenin also played the role of the town undertaker Vernon Shank in the Hulu original series Quick Draw.
Confidential, Moonlight Mile, Dude, Where's My Car?, where he played one of the space nerds, the 2009 film Star Trek, where he appeared as a ship yard worker who interacts with Kirk, Wish I Was Here, and Paul Blart 2.