Amandla Stenberg as Maddy Whittier

Nick Robinson as Olly Bright

Anika Noni Rose as Dr. Pauline Whittier

Ana de la Reguera as Carla Romero

Taylor Hickson as Kayra Bright

Danube R. Hermosillo as Rosa Romero

Dan Payne as Joe Bright

Fiona Loewi as Mae Bright

Robert Lawrenson as Mr. Waterman

Peter Benson as Dr. Chase

Françoise Yip as Dr. Francis

Marion Eisman as Nurse Janet

Farryn VanHumbeck as Ruby

Allison Riley as Police Officer

Sage Brocklebank as Astronaut

Valareen Friday as Surf Shop Cashier