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)

Jason Robinson as The Puma (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)