He also appeared in a recurring role as oncologist (and sexual deviant) Dr. Paul Zeltzer in the TV series Scrubs, and the aptly named Slow Roger in My Name Is Earl. He has a recurring role on the ABC-TV comedy Cougar Town as a neighbor who has a crush on the main character played by Courteney Cox.
He has appeared as quirky characters in numerous shows: Popular, Charmed, Ugly Betty, That '70s Show, Felicity, Weeds and Desperate Housewives. He also appeared as a Vidiian surgeon in an episode of Star Trek: Voyager and can be seen in the 2009 film Star Trek, as the ship yard worker that comments on, then receives, Kirks motorcycle at the shipyard.
He appeared in "Space: Above and Beyond" as Mank (1 episode, 1996),
as well as playing one of the space nerds in the movie Dude, Where's My Car? (credited as Robert Clendewin).
He also appeared in a commercials for Jack In The Box, and GoDaddy.
Clendenin also starred as devil-may-care Ted in the 2008 film short Daryl From OnCar. This short was produced for WGA-affiliated StrikeTV, a site created to benefit crew affected by the writer's strike of Nov 5, 2007 - Feb 12 2008.
He also had a small role in L.A. Noire as the drunken high school friend of Cole Phelps.
He appeared as Earl, a minor character on That 70's Show.
He currently appears as Dr. Terrence, a morgue assistant on The Closer.
He recently appeared in a State Farm commercial.
Clendenin graduated from Cornell University in 1986 and earned his Master of Fine Arts from Penn State University in 1990.