Boris Karloff as The Monster

Colin Clive as Henry Frankenstein

Valerie Hobson as Elizabeth

Ernest Thesiger as Doctor Pretorius

Elsa Lanchester as Mary Wollstonecraft Shelley / The Monster's Mate

Gavin Gordon as Lord Byron

Douglas Walton as Percy Bysshe Shelley

Una O'Connor as Minnie

E. E. Clive as Burgomaster

Lucien Prival as Butler

O. P. Heggie as Hermit

Dwight Frye as Karl

Reginald Barlow as Hans

Mary Gordon as Hans' Wife

Anne Darling as Shepherdess

Ted Billings as Ludwig

Billy Barty as Baby (uncredited)

Robert Adair as Hunter in Woods (uncredited)

Norman Ainsley as Archbishop (uncredited)

Frank Benson as Villager (uncredited)

Maurice Black as Gypsy (uncredited)

Walter Brennan as Peasant (uncredited)

Mae Bruce as Villager (uncredited)

A.S. Byron as King Homunculus (uncredited)

John Carradine as Lost Hunter at Hermit's Cottage (uncredited)

D'Arcy Corrigan as Procession Leader (uncredited)

Grace Cunard as Villager (uncredited)

J. Gunnis Davis as Uncle Glutz (uncredited)

Marie DeForrest as Ballerina (uncredited)

Elspeth Dudgeon as Gypsy's Mother (uncredited)

Helen Jerome Eddy as Gypsy's Wife (uncredited)

Neil Fitzgerald as Rudy (uncredited)

Brenda Fowler as Mother (uncredited)

John George as Villager (uncredited)

Helen Gibson as Villager (uncredited)

Marilyn Harris as Girl (uncredited)

Carmencita Johnson as Friend of Murdered Girl (uncredited)

Rollo Lloyd as Neighbor (uncredited)

Murdock MacQuarrie as Sympathetic Villager (uncredited)

Josephine McKim as Little Mermaid (uncredited)

Torben Meyer as Victim in flashback (uncredited)

Edwin Mordant as Coroner (uncredited)

Charles Murphy as Guard (uncredited)

Joseph North as Servant (uncredited)

Helen Parrish as Communion Girl (uncredited)

Edward Peil Sr. as Villager (uncredited)

Tempe Pigott as Auntie Glutz (uncredited)

Sarah Schwartz as Marta (uncredited)

Peter Shaw as Devil (uncredited)

Mary Stewart as Neighbor (uncredited)

Frank Terry as Lost Hunter at Hermit's Cottage (uncredited)

Anders Van Haden as Villager (uncredited)

Dorothy Vernon as Maid (uncredited)

Lucio Villegas as Priest (uncredited)

Joan Woodbury as Queen Homunculus (uncredited)