← Back to filmFilm · CastFull castThe Mystery of Mr. XOn screenCast8 credited performersRobert MontgomeryNicholas RevelElizabeth AllanJane FrenshamLewis StonePolice Superintendent ConnorRalph ForbesSir Christopher MarcheHenry StephensonSir Herbert FrenshamForrester HarveyJoe PalmerIvan F. SimpsonHutchinsonLeonard MudieMr. X