Cast

• Lewis MacDougall — Conor O'Malley
• Sigourney Weaver — Grandma
• Felicity Jones — Lizzie O'Malley (Mum)
• Toby Kebbell — Dad
• Ben Moor — Mr. Clark
• James Melville — Harry
• Jennifer Lim — Miss Kwan
• Frida Palsson — Lily's Mum
• Wanda Opalinska — Female Nurse
• Geraldine Chaplin — The Head Teacher
• Liam Neeson — The Monster (voice)
• Lily-Rose Aslandogdu — Lily