Joey King

Wren

Julia Goldani Telles

Hallie

Jaz Sinclair

Chloe

Annalise Basso

Katie

Alex Fitzalan

Tom

Taylor Richardson

Lizzie

Javier Botet

Slender Man

Michael Reilly Burke

Hallie's Dad

Kevin Chapman

Mr. Jensen

Miguel Nascimento

Kyle

Oscar Wahlberg

Boy with Glasses

Kris Sidberry

Librarian

Kayla Caulfield

High School Student (uncredited)

Jeffrey Corazzini

Police Officer (uncredited)

Michael Tow

Calculus Teacher (uncredited)

Kieran Tuomey

Student (uncredited)

Gabrielle Lorthe

Cheerleader (uncredited)