Benedict Cumberbatch (Louis Wain), Claire Foy (Emily Richardson-Wain), Andrea Riseborough (Caroline Wain), Toby Jones (Sir William Ingram), Sharon Rooney (Josephine Wain), Aimee Lou Wood (Claire Wain), Hayley Squires (Marie Wain), Stacy Martin (Felicie Wain), Julian Barratt (Dr. Elphick), Richard Ayoade (Henry Wood), Daniel Rigby (Bendigo), Taika Waititi (Max Kase), Jamie Demetriou (Woodville Jr.), Phoebe Nicholls (Mrs. Wain), Nick Cave (H.G. Wells), Asim Chaudhry (Herbert Railton), Stewart Scudamore (Dr. Quantock), Sophia Di Martino (Judith), Crystal Clarke (Alicia Simmonds), Dorothy Atkinson (Mrs. Du Frayne), Adeel Akhtar (Dan Rider), Siobhan McSweeney (Dr. Cooke), Fehinti Balogun (Praga), Simon Munnery (Jem Mace), James Eeles (Zugschaffner), Indica Watson (junge Felicie Wain)