Joseph Gordon-Levitt
as Tom

Zooey Deschanel
as Summer

Geoffrey Arend
as McKenzie

Chloë Grace Moretz
as Rachel

Matthew Gray Gubler
as Paul

Clark Gregg
as Vance

Patricia Belcher
as Millie

Rachel Boston
as Alison

Minka Kelly
as Autumn

Charles Walker
as Millie's New Husband

Ian Reed Kesler
as Douche

Darryl Alan Reed
as Bus Driver

Valente Rodriguez
as Employee #1

Yvette Nicole Brown
as New Secretary

Nicole Vicius
as Partygoer

Natalie Boren
as Another Partygoer

Maile Flanagan
as Rhoda

Darryl Sivad
as Usher

Gregory A. Thompson
as Minister

Michael Bodie
as Man

John Mackie
as Mime

Jacob Stroop
as Cupid

Kevin Michael
as Wedding Singer

Sid Wilner
as Grossman

Richard McGonagle
as Narrator (voice)

Jean-Paul Vignon
as French Narrator (voice)

Bryan Anthony
as Dancer

Sybil Azur
as Dancer

Cheryl Baxter
as Dancer

Gustavo Carr
as Dancer

John R. Corella
as Dancer

Nadine Ellis
as Dancer

Alejandro Estornel
as Dancer

Nathaniel Flatt
as Dancer

Reshma Gajjar
as Dancer

Tiffany Granath
as Dancer

Jennifer Hamilton
as Dancer

Brandon Henschel
as Dancer

Michael Higgins
as Dancer

Kenneth Hughes
as Dancer

Alexandra Nicole Hulme
as Dancer

John Jacquet Jr.
as Dancer

Jennifer Lee Keyes
as Dancer

Tim Lacatena
as Dancer

Rebecca Lin
as Dancer

Gelsey Weiss
as Dancer

Katie Malia
as Dancer

Anthony Marciona
as Dancer

Christopher Martinez
as Dancer

Vivian Nixon
as Dancer

Tracy Phillips
as Dancer

Nathan Prevost
as Dancer

Jamie Shea
as Dancer

Ryan Thomas
as Dancer

Christian Vincent
as Dancer

Jull Weber
as Dancer

Olivia Howard Bagg
as Summer - Age 12 (uncredited)

Chris Connell
as Marcus (uncredited)

Samantha Krutzfeldt
as Charlie (uncredited)

Kathryn Weisbeck
as Summer Lookalike (uncredited)

Eileen Álvarez
as Summer Lookalike (uncredited)

Jennifer Hetrick
as Sarah (uncredited)

Pleasant Wayne
as Tavern Patron (uncredited)