Having guest starred in an episode of Full House at age 13, Lively returned to Los Angeles in the late 1990s and had a role in American Pie (1999). He followed this up on the television series So Weird, on which he played Carey Bell from 2000 to 2001. Lively was then a cast member of the short-lived 2003 Norm Macdonald series A Minute with Stan Hooper.
In 2005, Lively was offered two different television roles – on 24 and The L Word. He took the role on The L Word as documentary filmmaker Mark Wayland. He will reprise the role for the show’s upcoming third season.
Lively is also part of the cast of the upcoming series Modern Men, which will premiere in January 2006.