Justin Timberlake is a pop singer and an actor. Justin was a part of the Mickey Mouse Club. Justin is not bi. He does have a girlfriend. Her name is Jessica Biel. For more information please see: http://www.ask.com/wiki/Justin_Timberlake
There is no information to indicate that Justin Timberlake is bisexual. He applauded his former 'N Sync band mate Lance Bass for admitting his homosexuality, and Justin appears to be quite a lady's man.