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 Emmanuelle Chriqui Guest Star Michael Simpson Guest Star Todd Bosley Guest Star Ben Diskin Guest Star Kristen Pate Guest Star Mark L. Young Guest Star Ben Carrigan Guest Star Conor Deasy Guest Star Kevin Horan Guest Star Padraic McMahon Guest Star Daniel Ryan Guest Star Robert McMurrer Guest Star Josh Schwartz Executive Producer Doug Liman Executive Producer McG Executive Producer David Bartis Executive Producer Robert DeLaurentiis Executive Producer