Annie's life is a mess. But when she finds out her lifetime best friend is engaged, she simply must serve as Lillian's maid of honor. Though lovelorn and broke, Annie bluffs her way through the expensive and bizarre rituals. With one chance to get it perfect, she’ll show Lillian and her bridesmaids just how far you’ll go for someone you love.
| Annie Walker | Kristen Wiig |
| Lillian Donovan | Maya Rudolph |
| Helen Harris | Rose Byrne |
| Officer Rhodes | Chris O'Dowd |
| Rita | Wendi McLendon-Covey |
| Becca | Ellie Kemper |
| Megan Price | Melissa McCarthy |
| Ted | Jon Hamm |
| Judy Walker | Jill Clayburgh |
| Brynn | Rebel Wilson |
| Gil | Matt Lucas |
| Don Cholodecki | Michael Hitchcock |
| Douglas Price | Tim Heidecker |
| Mr. Donovan | Franklyn Ajaye |
| Mrs. Donovan | Lynne Marie Stewart |
| Rodney | Terry Crews |
| Whitney | Jessica St. Clair |
| Kahlua | Kali Hawk |
| Helen's Husband | Andy Buckley |
| Helen's Stepson | Matt Bennett |
| Helen's Tennis Partner | Nancy Carell |
| Carol | Melanie Hutsell |
| Carnie Wilson | Carnie Wilson |
| Chynna Phillips | Chynna Phillips |
| Wendy Wilson | Wendy Wilson |
| Oscar | Joe Nuñez |
| Jewelry Store Girl | Mia Rose Frampton |
| Jewelry Store Couple | Tom Yi |
| Jewelry Store Couple | Elaine Kao |
| Flight Attendant Steve | Mitch Silpa |
| Flight Attendant Claire | Dana Powell |
| Kevin | Greg Tuculescu |
| Pete | Brian Petsos |
| Air Marshall Jon | Ben Falcone |
| Bill Cozbi | Richard Riehle |
| Hostess (uncredited) | Suzanne LaChasse |
| Nervous Woman on Plane | Annie Mumolo |
| Girl at Shower | Jillian Bell |
| Girl at Shower | Ariane Price |
| Wedding Guest (uncredited) | Paul Feig |
| Annie's Mistaken Husband | Steve Bannos |
| Annie's Mistaken Fella | Hugh Dane |
| Churra Chi Waiter | Eloy Casados |
| Helen's Stepdaughter | Molly Buffington |
| Tyler (as Blake Garrett) | Blake Garrett Rosenthal |
| Flight Attendant in Coach | Angelica Acedo |
| 13-Year-Old Girl's Father | Joel Madison |
| Butler | R.F. Daley |
| Horseman | Jordan Black |
| Doorman at Shower | David Hoffman |
| Shower Waiter | Frederik Hamel |
| Minister | Jimmy Brogan |
| Old Woman in Car (uncredited) | Pat Carroll |
| Obnoxious Ice Skater (uncredited) | Owen Daniels |
| Valet (uncredited) | Greg Worswick |
| Lillian's Aunt (uncredited) | Joyce Lakin |
| Brazilian Waiter (uncredited) | Tony Sagastizado I |
