Paul Rudd as Peter Klaven

Jason Segel as Sydney Fife

Rashida Jones as Zooey Rice

Andy Samberg as Robbie Klaven

J.K. Simmons as Oswald Klaven

Jane Curtin as Joyce Klaven

Jon Favreau as Barry

Jaime Pressly as Denise

Rob Huebel as Tevin Downey

Thomas Lennon as Doug

Sarah Burns as Hailey

Lou Ferrigno as Lou Ferrigno

Greg Levine as Hailey's Date

Jean Villepique as Leanne

Kym Whitley as Female Co-Worker

Colleen Crabtree as Female Co-Worker

Caroline Farah as Female Co-Worker

Mather Zickel as Gil

Aziz Ansari as Eugene

Nick Kroll as Larry

Liz Cackowski as Zooey's Friend

Kulap Vilaysack as Zooey's Friend

Catherine Reitman as Zooey's Friend

Carla Gallo as Zooey's Friend

Vicki Davis as Zooey's Friend

Josh Cooke as Alan (Bench Press Guy)

Jay Chandrasekhar as Barry's Buddy

Seth Morris as Barry's Buddy

James P. Engel as Barry's Buddy

Jerry Minor as Berry's Buddy

Joe Lo Truglio as Lonnie (Voice Crack Guy)

Murray Gershenz as Mel Stein

Keri Safran as JAR Waitress

Greg Tuculescu as Open House Couple

Ian Roberts as Venice Broadwalk Jogger

Bob Cicherillo as Venice Boardwalk Bodybuilder

Ethan S. Smith as Sidney's Buddy

Nelson Franklin as Sidney's Buddy

Ping Wu as Mr. Chu

Jill Bartlett as Woman Leaving Sydney's House

Matt Walsh as Impatient Golfer

Geddy Lee as Geddy Lee - Rush

Alex Lifeson as Alex Lifeson - Rush

Neil Peart as Neil Peart - Rush

Melissa Rauch as Woman Jogger Yelling at Sydney

David Wain as Wedding Photographer

Raquel Bell as Saks Fifth Avenue Saleswoman

Larry Wilmore as Justice Of The Peace

Dennis James Anderson as Hank Mardukas

Craig Wedren as Wedding Band

Damian Kulash as Wedding Band

Timothy Nordwind as Wedding Band

Dan Konopka as Wedding Band

Andy Ross as Wedding Band

David Krumholtz as Sydney's Buddy (uncredited)

Sidow Sobrino as Rush Concert Fan (uncredited)