Vo filme 500 dní so Summer hrajú Joseph Gordon-Levitt (Tom), Zooey Deschanel (Summer), Geoffrey Arend (McKenzie), Chloë Grace Moretz (Rachel), Matthew Gray Gubler (Paul), Clark Gregg (Vance), Patricia Belcher (Millie), Rachel Boston (Alison), Minka Kelly (Autumn), Charles Walker (Millie's New Husband), Ian Reed Kesler (Douche), Darryl Alan Reed (Bus Driver), Valente Rodriguez (Employee #1), Yvette Nicole Brown (New Secretary), Nicole Vicius (Partygoer), Natalie Boren (Another Partygoer), Maile Flanagan (Rhoda), Darryl Sivad (Usher), Gregory A. Thompson (Minister), Michael Bodie (Man), John Mackie (Mime), Jacob Stroop (Cupid), Kevin Michael (Wedding Singer), Sid Wilner (Grossman), Richard McGonagle (Narrator (voice)), Jean-Paul Vignon (French Narrator (voice)), Bryan Anthony (Dancer), Sybil Azur (Dancer), Cheryl Baxter (Dancer), Gustavo Carr (Dancer), John R. Corella (Dancer), Nadine Ellis (Dancer), Alejandro Estornel (Dancer), Nathaniel Flatt (Dancer), Reshma Gajjar (Dancer), Tiffany Granath (Dancer), Jennifer Hamilton (Dancer), Brandon Henschel (Dancer), Michael Higgins (Dancer), Kenneth Hughes (Dancer), Alexandra Nicole Hulme (Dancer), John Jacquet Jr. (Dancer), Jennifer Lee Keyes (Dancer), Tim Lacatena (Dancer), Rebecca Lin (Dancer), Gelsey Weiss (Dancer), Katie Malia (Dancer), Anthony Marciona (Dancer), Christopher Martinez (Dancer), Vivian Nixon (Dancer), Tracy Phillips (Dancer), Nathan Prevost (Dancer), Jamie Shea (Dancer), Ryan Thomas (Dancer), Christian Vincent (Dancer), Jull Weber (Dancer), Olivia Howard Bagg (Summer - Age 12 (uncredited)), Chris Connell (Marcus (uncredited)), Samantha Krutzfeldt (Charlie (uncredited)), Kathryn Weisbeck (Summer Lookalike (uncredited)), Eileen Álvarez (Summer Lookalike (uncredited)), Jennifer Hetrick (Sarah (uncredited)), Pleasant Wayne (Tavern Patron (uncredited)).