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 Michael Cassidy Guest Star Shannon Lucio Guest Star Barry Newman Guest Star Kim Delaney Guest Star Bruce Katzman Guest Star David DiBrienza Guest Star Rachel Yamagata Guest Star Lincoln Thompson Guest Star Josh Schwartz Executive Producer Doug Liman Executive Producer McG Executive Producer David Bartis Executive Producer Robert DeLaurentiis Executive Producer