Olivia Cooke

Amanda

Anya Taylor-Joy

Lily

Anton Yelchin

Tim

Paul Sparks

Mark

Francie Swift

Cynthia

Kaili Vernoff

Karen

Alyssa Fishenden

Jessica

Jackson Damon

Phil

James Haddad

Michael

Nolan Ball

Delivery Guy

Celeste Oliva

Receptionist

Stephanie Atkinson

Knitting Therapist (uncredited)

Lauren Laperriere

Mental Patient (uncredited)

Thomas Dings

Teenager (uncredited)

Leah Procito

Doctor (uncredited)

Alex Wolff

Party Friend (uncredited)

Xavier Dillingham

Party Goer (uncredited)

Jack Norton

Mental Patient (uncredited)

Daniel Martignetti

CT State Policeman (uncredited)