Cast & crew
You'll Find Out (1940)
Directed by David Butler Written by James V. Kern, David Butler
Cast
| Kay Kyser | Himself |
| Peter Lorre | Fenninger |
| Boris Karloff | Spencer |
| Bela Lugosi | Prince Luca |
| Helen Parrish | Janis |
| Dennis O'Keefe | Chuck Jr. |
| Alma Kruger | Margo |
| Joseph Eggenton | Jurgen Borchert |
| Ginny Simms | Herself |
| Harry Babbitt | Himself |
| M.A. Bogue | Ish |
| Sully Mason | Himself |
| Mary Bovard | (uncredited) |
| Jeff Corey | Corey |
| Louise Currie | (uncredited) |
| Bess Flowers | (uncredited) |
| Jeanne Houser | (uncredited) |
| Richard Kipling | Script |
| Eleanor Lawson | Gaby |
| Larry McGrath | Complainer |
| Frank Mills | Cabbie |
| Mimi Montaye | (uncredited) |
| Dorothy Moore | Penny |
| Leonard Mudie | Fenninger |
| Joseph North | Servant |
| Frank O'Connor | Responder |
| Mary Martha Wood | Georgia |
| Beulah Parkington | (uncredited) |
| Jane Patten | (uncredited) |
| Eugenia Rafee | Maid |
| William Telaak | (uncredited) |
| Joan Warner | (uncredited) |
| Guy Webster | (uncredited) |
Crew
| Vernon L. Walker | Special Effects |
| Edward Stevenson | Costume Design |
| Frank Redman | Cinematography |
| James V. Kern | Screenplay |
| David Butler | Director |
| David Butler | Producer |
| James V. Kern | Story |
| David Butler | Story |
| Fred Fleck | Assistant Director |
| Irene Morra | Editor |