Samuel Blenkin

as Boy Kavalier

Babou Ceesay

as Kumi Morrow

Sydney Chandler

as Wendy

Alex Lawther

as Joe Hermit

Essie Davis

as Dame Sylvia

Adarsh Gourav

as Slightly

Timothy Olyphant

as Kirsh

Jonathan Ajayi

as Smee

Erana James

as Curly

Lily Newmark

as Nibs