Willa Fitzgerald
Kitsey Barbour

Aneurin Barnard
Boris Pavlikovsky

Finn Wolfhard
Young Boris Pavlikovsky

Ashleigh Cummings
Pippa

Aimee Laurence
Young Pippa

Robert Joy
Welton 'Welty' Blackwell

Boyd Gaines
Mr. Barbour
Carly Connors
Young Kitsey Barbour

Luke Kleintank
Platt Barbour

Hailey Wist
Theo's Mother