Sophie Nélisse
Gilly Hopkins
Glenn Close
Nonnie Hopkins
Octavia Spencer
Miss Harris
Julia Stiles
Courtney Rutherford Hopkins
Richard Topol
Principal Evans
Johanna Day
Principal Maynard
Frank Oz
Cookie Monster (voice)
Blanca Camacho
Additional Voices (voice)
Athena Stuebe
Neighbor and Student
Connor Keegan Dosch
School student
Cara Cooper
Woman with Book