Peter Gallagher Sandy Cohen Actor Ben McKenzie Ryan Atwood Actor Kelly Rowan Kirsten Cohen Actor Adam Brody Seth Cohen Actor Mischa Barton Actor Rachel Bilson Summer Roberts Actor Melinda Clarke Julie Cooper Actor Alan Dale Actor Olivia Wilde Guest Star Johnny Messner Guest Star Billy Campbell Guest Star Leanna Campbell Guest Star George Contreras Guest Star Brandt Jacobus Guest Star Taivon McKinney Guest Star Carrie Ann Nagy Guest Star Caitlin Kazepis Guest Star Steve Sornbutnark Guest Star Meg Anderson Guest Star Amy Clover Guest Star Shaun Cozzens Guest Star Josh Schwartz Executive Producer Doug Liman Executive Producer McG Executive Producer David Bartis Executive Producer Robert DeLaurentiis Executive Producer