 James Robertson JusticeSir Ernest "Lieutenant M.J. Farrow, RN" Pease, KBE, FRS | Sir Ernest "Lieutenant M.J. Farrow, RN" Pease, KBE, FRS |
 Leslie PhillipsFlying Officer Jimmy Cooper | Flying Officer Jimmy Cooper |
 Stanley BaxterFlying Officer S. "Jock" Everett / Major Stamfel | Flying Officer S. "Jock" Everett / Major Stamfel |
 Eric SykesSports Officer Willoughby | Sports Officer Willoughby |
 Richard WattisEntertainments Officer Woodcock | Entertainments Officer Woodcock |
| GGodfrey WinnSelf | Self |
 Colin GordonBriggs | Briggs |
 John Le MesurierEscape Officer Piggott | Escape Officer Piggott |
 Norman BirdSenior British Officer Travers | Senior British Officer Travers |
 Jeremy LloydFlight Lieutenant J.J. "Bonzo" Baines, DFC | Flight Lieutenant J.J. "Bonzo" Baines, DFC |
 John ForrestLieutenant Hans "'Grassy' Green" Kringling | Lieutenant Hans "'Grassy' Green" Kringling |
 Jean CadellMrs. MacDougall | Mrs. MacDougall |
 Peter MyersFlying Officer P.R. Shaw | Flying Officer P.R. Shaw |
 Ronnie StevensHankley | Hankley |
 Ronald Leigh-HuntClynes | Clynes |
 Steve PlytasLuftwaffe Officer | Luftwaffe Officer |
| JJohn RinghamFlying Officer G.S. "Plum" Poudding | Flying Officer G.S. "Plum" Poudding |
| MMark HardyPrisoner of War | Prisoner of War |
| JJohn HusonSenior RAF Officer | Senior RAF Officer |
 Joseph FürstLuftwaffe Interrogator | Luftwaffe Interrogator |
 Norman ShelleyFred Whittaker | Fred Whittaker |
 Brian OultonScientist in Corridor | Scientist in Corridor |
 Frederick PiperScientist in Corridor | Scientist in Corridor |
| JJoan HaythorneMiss Rogers | Miss Rogers |
| HHeidi ErichGerman Frau | German Frau |
| LLesley AllenGerman Frau | German Frau |
 Derek AylwardStagehand (uncredited) | Stagehand (uncredited) |
 Vincent BallHiggins (uncredited) | Higgins (uncredited) |
| RRon CarrGerman Guard (uncredited) | German Guard (uncredited) |
| TTony CastletonStagehand (uncredited) | Stagehand (uncredited) |
