Hannah Waddingham
— Narrator (voice)
Lolly Adefope
— Miss Skate (Voice)
Jayde Adams
— Plaice (voice)
Rob Brydon
— Fisherman / Whale / Starfish / Anchovy (voice)
Reuben Kirby
— Tiddler (voice)
Theo Fraser
— Johnny Dory (voice)
Paul Thornley
— Lobster (voice)
Andy Martin
— Seal (voice)
Lizzie Waterworth
— Additional Voices (voice)