Bret Harrison gained widespread attention when he was cast in the FOX sitcom "The Loop". Harrison had been appearing in nightclubs around the Los Angeles area in the band "Big Japan" where he plays the guitar with fellow friend, Adam Brody, playing the drums.

Harrison appeared in the movie "Lightning Bug" which premiered in Los Angeles and Philadelphia in 2004. Scott Weinberg's review says "Bret Harrison absolutely anchors the film with his fantastic portrayal of Green; he's effortlessly likable and entirely believable as a young man focused on the stars while nailed to the pavement".

Bret was a recurring guest star on Warner Brothers TV's sitcom "Grounded for Life". Bret played Brad O'Keefe and was the next door neighbor to the Finnerty's in this smash sitcom on WB. "Grounded for Life" reruns will now appear on ABC Family Channel.

Harrison also guest starred in episodes of "Boston Public" and "Law and Order: Special Victims Unit".

Bret made his movie debut in "Orange County" which premiered January 11th, 2002.

He also starred in a MTV movie called "Everybody's Doing It". He played Travis in this movie about high school abstinence programs.