Chloë Grace Moretz as Mia Hall

Jamie Blackley as Adam Wilde

Liana Liberato as Kim Schein

Mireille Enos as Kat Hall

Joshua Leonard as Denny Hall

Stacy Keach as Gramps

Gabrielle Rose as Gran

Jakob Davies as Teddy Hall

Ali Milner as Liz

Aisha Hinds as Nurse Ramirez

Gabrielle Cerys Haslett as Young Mia

Lauren Lee Smith as Willow

Adam Solomonian as Henry

John Emmet Tracy as Surgeon

Chelah Horsdal as Liddy

Christine Willes as Nurse Davis

Arielle Tuliao as Astrid

Sarah Grey as Cute Groupie

William Vaughan as Male EMT

Paul Jarrett as Surgeon

Giles Panton as Teddy's Surgeon

Dave Collette as Orderly

David Orth as Surgeon for Driver

Camille Atebe as Nurse

Annabel Kershaw as Wife of Driver

Toby Hargrave as Mosh Pit Oaf

Primo Allon as Punker

John Shaw as Music Aficionado

Michael Adamthwaite as Security Guard

Jameson Trenholm as Skeleton

Donnie MacNeil as Cool Rocker Guy

Genevieve Buechner as Cute Groupie #2

Alisa Weilerstein as Herself

Elisa King as Autograph Girl

Brett Wise as Bartender

Steven Jeays as High Five Guy

Boyd Ferguson as Orderly #2

Sylvesta Stuart as Security Guard #2

Ben Klassen as Willamette Stone Band

Ryan Stephenson as Willamette Stone Band

Tom Vanderkam as Willamette Stone Band

Tony Dubroy as Bassist for Nasty Bruises

Aliyah O'Brien as Female EMT

Jessica Rotter as Mia's Chorus Girl (uncredited)