| starring in order of appearance |
| Ezra Miller | ... Robert |
| Jeremy Allen White | ... Dave |
| Emory Cohen | ... Trevor |
| Michael Stuhlbarg | ... Mr. Burke |
| Addison Timlin | ... Amy |
| David Costable | ... Mr. Anderson |
| Rosemarie DeWitt | ... Ms. Vogel |
| Dariusz Michal Uczkowski | ... Peter |
| Gary Wilmes | ... Mr. Virgil |
| Lee Wilkof | ... Mr. Wiseman |
| Paul Sparks | ... Det. Eclisse |
| Bill Raymond | ... Mr. Williams |
| Alexandra Neil | ... Gloria Talbert |
| Mark Zeisler | ... Tom Talbert |
| Christopher McCann | ... Mr. Ullman |
|
| also starring |
| Byrdie Bell | ... Cherry Dee |
| Mary Michelson | ... Talbert Twin |
| Carly Michelson | ... Talbert Twin |
|
| Rebecca Boughton | ... Broken Glass Girl 1 |
| Anna Maliere | ... Broken Glass Girl 2 |
| Dani Baum | ... Broken Glass Girl 3 |
| Julian Branciforte | ... Freshman Student |
| Marta Miller | ... Robert's Mom (voice) |
| Annette Foisy | ... Nurse |
| Paige Billings | ... AV Class Girl |
| Tony Costagliola | ... Senior Druggie |
| Cameron Ward | ... Boys Dorm Head |
| Richard White | ... Dave's Dad in Car |
| Christopher Brisson | ... Security Guard |
| Mackenzie Deary | ... Chapel Student |
| Will Childs | ... Chapel Teacher |
| Javier Alvarez | ... Math Teacher |
|
| Screaming Seniors |
| Effrem Adams | ... Screaming Senior |
| Robert Malitsky | ... Screaming Senior |
| Robert Saunders | ... Screaming Senior |
| Andrew Corkin | ... Screaming Senior |
|
| Robert's Memorial Video |
| Laura Boucher | ... Robert's Memorial Video |
| Rosamund Dunn | ... Robert's Memorial Video |
| Timothy Dreary | ... Robert's Memorial Video |
| Mike Thomas | ... Robert's Memorial Video |
| Emily Potrzeba | ... Robert's Memorial Video |
| Paul Kramarz | ... Robert's Memorial Video |
|
| School Memorial Video |
| Jacob Allard | ... School Memorial Video |
| Amber Allard | ... School Memorial Video |
| Kristiana Sumera | ... School Memorial Video |
| Brittney Roy | ... School Memorial Video |
| Chloe Bates | ... School Memorial Video |
| Allyse Rosen | ... School Memorial Video |
|
| Featured Extras |
| John Basnight | ... Extra |
| Catie Botting | ... Extra |
| Beckam Cela | ... Extra |
| Alex Labeef | ... Extra |
| Harrison Lees | ... Extra |
| Colin Sebastian | ... Extra |
