Odessa Young as Lily Colson

Hari Nef as Bex Warren

ABRA as Em Lacey

Suki Waterhouse as Sarah Lacey

Anika Noni Rose as Nancey Lacey

Colman Domingo as Principal Turrell

Maude Apatow as Grace

Bella Thorne as Reagan Hall

Joel McHale as Nick Mathers

Bill Skarsgård as Mark

Cody Christian as Johnny

Kathryn Erbe as Rebecca Colson

Susan Misner as Rose Mathers

Danny Ramirez as Diamond

Kelvin Harrison, Jr. as Mason

Noah Galvin as Marty

Joe Chrest as Lawrence

Jeff Pope as Officer Ritcher

Jennifer Morrison as Margie Duncan

J.D. Evermore as Chief Patterson

Lukas Gage as Eric Lafont

Cullen Moss as Mayor Bartlett

Stacie Davis as Langley

Destiny Reed as Allie

Liz Elkins Newcomer as Mrs. Bartlett

Wolfgang Novogratz as Dave

Isabella Esposito as Nikki

Lucy Faust as Alexis Turrell

Geraldine Singer as Lisa Sanders

Caden Swain as Donny

Andrene Ward-Hammond as Officer Daniels

Silas Cooper as Grace's Father

Toney Chapman Steele as Angry Mob (uncredited)

Colby Slayter as Red Hat Football Player (uncredited)

William Schaff as Masked Man (uncredited)

Rey Reynaud as Masked Neighbor / Diamond Body Double (uncredited)

Austin William Morgan as Student (uncredited)

Bruce Vincent Logan as Masked Gunman (uncredited)

Felicity Lartigue as Cheerleader (uncredited)

Emily LaGroue as Cheerleader (uncredited)

Stephanie Davis Holmes as Citizen (uncredited)

Josephine Hennessey as Masked Townsperson (uncredited)

Paisley Gant as Student (uncredited)

Sarah-Grace Donnelly as Student (uncredited)

Kirsten Bazet as A / V Club Student (uncredited)

April Asbury as Mob Patron (uncredited)

Issa Abou-Issa as Masked Person (uncredited)

Rachel Whitman Groves as Woman in House

Greg DiLeo as Salem Resident 2

T.C. Carter as Snap Back

Ariel Fournier as Salem High Girl

Christopher Berry as Salem Resident 1

Kennon Kepper as Teammate 2

Gabriel Orion McCulloch as Tank Top

Anthony Marble as Marty's Father

Charley Vance as Guy in Street

Daniel Williams-Lopez as Stone-Faced Teen

Lance E. Nichols as FBI Agent Richard Vernon

Leticia Jimenez as Diamond's Mom

Lorelei Gilbert as Carlie

Tom McCafferty as Some Guy

Ben Matheny as Passenger

Ann Mahoney as Mom in Supermarket

Jacob A. Brown as Teammaye