 | Cedric Hardwicke als Richard Cobb |
 | Vincent Price als Geoffrey Radcliffe |
 | Nan Grey als Helen Manson |
 | John Sutton als Dr. Frank Griffin |
 | Cecil Kellaway als Inspector Sampson |
 | Alan Napier als Willie Spears |
 | Forrester Harvey als Ben Jenkins |
 | Ernie Adams als Minor Role (uncredited) |
 | Jimmy Aubrey als Plainclothesman (uncredited) |
 | Walter Bacon als Fight Spectator (uncredited) |
 | Billy Bevan als Jim (uncredited) |
| Clara Blore als Woman (uncredited) |
 | Stanley Blystone als Minor Role (uncredited) |
 | Matthew Boulton als Policeman (uncredited) |
 | Ed Brady als Policeman (uncredited) |
 | Chet Brandenburg als Miner at Colliery (uncredited) |
 | Louise Brien als Griffin's Secretary (uncredited) |
 | Charles Brokaw als Minor Role (uncredited) |
 | Jean Brooks als Minor Role (uncredited) |
| Tom Coleman als Miner at Colliery (uncredited) |
| Frank Coletti als Minor Role (uncredited) |
 | Harry Cording als Miner (uncredited) |
| Paul England als Detective (uncredited) |
 | Rex Evans als Constable Briggs (uncredited) |
 | Mary Field als Passerby at Willie's House (uncredited) |
 | Edward Fielding als Prison Governor (uncredited) |
| Raoul Freeman als Detective (uncredited) |
 | Mary Gordon als Cookie (uncredited) |
| Sidney Grayler als Minor Role (uncredited) |
 | Kit Guard als Miner at Colliery (uncredited) |
 | Frank Hagney als Bill (uncredited) |
| Bobby Hale als Miner at Colliery (uncredited) |
| Barry Hays als Minor Role (uncredited) |
| Frank Hill als Policeman (uncredited) |
 | Leyland Hodgson als Chauffeur (uncredited) |
| Hugh Huntley als Secretary (uncredited) |
| George Hyde als Miner at Radcliffe Colliery (uncredited) |
| Ellis Irving als Miner at Radcliffe Colliery (uncredited) |
 | Boyd Irwin als Minor Role (uncredited) |
 | Dick Johnstone als Miner at Colliery (uncredited) |
 | Colin Kenny als Plainclothesman (uncredited) |
| George Kirby als Miner at Radcliffe Colliery (uncredited) |
 | Bruce Lester als Chaplain (uncredited) |
 | George Lloyd als Miner at Radcliffe Colliery (uncredited) |
| Jack Low als Miner at Colliery (uncredited) |
 | Edmund MacDonald als Miner at Radcliffe Colliery (uncredited) |
 | William Newell als Minor Role (uncredited) |
 | Frank O'Connor als Constable at Coal Train (uncredited) |
| Alexander Pollard als Footman (uncredited) |
 | Frances Robinson als Clinic Nurse (uncredited) |
| Robert Robinson als Miner at Colliery (uncredited) |
 | Ivan F. Simpson als Mr. Cotton (uncredited) |
 | Harry Stubbs als Constable Tewsbury (uncredited) |
| Denis Tankard als Miner at Radcliffe Colliery (uncredited) |
| Cyril Thornton als Policeman (uncredited) |
| David Thursby als Bob (uncredited) |
 | Crane Whitley als Minor Role (uncredited) |
| Eric Wilton als Fingerprint Expert (uncredited) |
| Jack Otterson | Art Direction |
| Vera West | Costume Design |
| Russell A. Gausman | Set Decoration |
| Joe May | Director |
| Milton Krasner | Director of Photography |
| Hans J. Salter | Original Music Composer |
| Lester Cole | Screenplay |
| Frank Skinner | Original Music Composer |
| Curt Siodmak | Screenplay |
| Joe May | Story |
| Frank Gross | Editor |
| John P. Fulton | Visual Effects |
| Curt Siodmak | Story |
| H.G. Wells | Characters |
| David S. Horsley | Special Effects |
| Charles Previn | Music Director |
| Cedric Belfrage | Additional Writing |
| Ken Goldsmith | Associate Producer |
| Phil Karlson | Assistant Director |
| Martin Obzina | Art Direction |
| Bernard B. Brown | Sound Supervisor |
| William Hedgcock | Sound Engineer |
| Cleo E. Baker | Visual Effects |
