Jack Black

Satan

Robert Timothy Smith

Liam Turner

Keegan-Michael Key

Dr. Finkleman

Brianne Howey

Molly Turner

Hayes MacArthur

Bill Turner

P.J. Byrne

Mr. Charles

Jaden Carson Baker

Gibby

Kai Cech

Emma

Post Malone

Post Malone

Gavin Munn

Aidan

Cate Freedman

Crossing Guard

Ben Stiller

Lucifer (uncredited)

Kyle Gass

Science Teacher

Leo Easton Kelly

Spencer

Tierre Turner

Blitzen (voice)

Travon McEntyre

Male Nurse

Selah Kimbro Jones

Attractive Girl

Abe Farrelly

Tattoo Tony