Bella Ramsey as Hilda[4] Daisy Haggard as Mum Ameerah Falzon-Ojo as Frida Oliver Nelson as David Ilan Galkoff as David (singing voice)[4] Rasmus Hardiker as Alfur Kaisa Hammarlund as Additional Voices [4] Reece Pockney as Trevor/Additional Voices[4] Simon Greenall as Additional Voices Ako Mitchell as Additional Voices Claire Skinner as Additional Voices Nina Sosanya as Additional Voices Ólafur Darri Ólafsson