 Bud AbbottCuthbert Greenway / Dr. Ralph Greenway | Cuthbert Greenway / Dr. Ralph Greenway |
 Lou CostelloHoratio Prim | Horatio Prim |
 Marjorie ReynoldsMelody Allen | Melody Allen |
 Binnie BarnesMildred Dean | Mildred Dean |
 John SheltonSheldon Gage | Sheldon Gage |
 Gale SondergaardEmily | Emily |
 Lynn BaggettJune Prescott | June Prescott |
 Jess BarkerThomas Danbury | Thomas Danbury |
 Ann GillisNora O'Leary | Nora O'Leary |
 Donald MacBrideLt. Mason | Lt. Mason |
 William HallSgt. Conners | Sgt. Conners |
 Robert BarratMaj. Putnam | Maj. Putnam |
 Rex LeaseSgt. Makepeace | Sgt. Makepeace |
 Kirk AlynDandy at Party (uncredited) | Dandy at Party (uncredited) |
| HHarry BrownSecond Sergeant (uncredited) | Second Sergeant (uncredited) |
 George M. CarletonMuseum Guard (uncredited) | Museum Guard (uncredited) |
 Wheaton ChambersBill - Museum Guard (uncredited) | Bill - Museum Guard (uncredited) |
| JJames ConatyParty Guest (uncredited) | Party Guest (uncredited) |
 John CrawfordDandy at Party (uncredited) | Dandy at Party (uncredited) |
 Vernon DowningLeigh - Traitor (uncredited) | Leigh - Traitor (uncredited) |
 Marjorie EatonBessie - Danbury's Maid (uncredited) | Bessie - Danbury's Maid (uncredited) |
 Myron HealeyDandy at Party (uncredited) | Dandy at Party (uncredited) |
 Boyd IrwinCranwell - Traitor (uncredited) | Cranwell - Traitor (uncredited) |
 Selmer JacksonMr. Dibbs - Museum Curator (uncredited) | Mr. Dibbs - Museum Curator (uncredited) |
 William H. O'BrienDanbury Servant (uncredited) | Danbury Servant (uncredited) |
| SScott ThomsonDandy at Party (uncredited) | Dandy at Party (uncredited) |
| HHarry WoolmanMotorcycle Rider (uncredited) | Motorcycle Rider (uncredited) |
