Owen Wilson as Dupree

Kate Hudson as Molly

Matt Dillon as Carl

Michael Douglas as Mr. Thompson

Seth Rogen as Neil

Amanda Detmer as Annie

Ralph Ting as Toshi

Todd Stashwick as Tony

Bill Hader as Mark

Lance Armstrong as Lance Armstrong

Jason Winer as Eddie

Sidney S. Liufau as Paco

Billy Gardell as Bartender Dave

Eli Vargas as Aaron

Houston Mack as Dougie

Bob Larkin as Army Veteran

Suzanne Ford as Thompson's Secretary

Claudia Choi as Carl's Secretary

Summer Altice as Stripper

Jeanine Hass as Stripper

Peter Ruocco as Wedding Planner

Joe Russo as Personnel Manager

Lance Irwin as Neighborhood Father

Fenessa Pineda as 2nd Grade Girl

Mario Revolori as 2nd Grade Boy

Jay Lembeck as Minister

Gil Harris as Reese

Pat Crawford Brown as Aunt Kathy

Bayani Ison as Hawaiian Bartender

Joe Wilson as Joe

Blaine Pate as Larry

Kevin Breznahan as Charlie

Trevor Stock as Herb

Sean Perrone as Ned

Craig Hosking as Pilot

Harry Dean Stanton as Curly (uncredited)

Amber Hay as Wedding Guest (uncredited)

Kepa Kruse as Waiter (uncredited)

Michelle Lee as Hawaiian Air Ticketing Agent (uncredited)

May Porter as Waitress (uncredited)

Tasha Smith as Co-Worker (uncredited)