Ronald Reagan as Professor Peter Boyd

Diana Lynn as Jane

Walter Slezak as Professor Hans Neumann

Lucille Barkley as Valerie Tillinghast

Jesse White as Babcock

Herbert Heyes as Dean Tillinghast

Herb Vigran as Lt. Daggett

Harry Tyler as Knucksy

Edward Clark as Fosdick (as Ed Clark)

Edward Gargan as Policeman (as Ed Gargan)

Joel Friedkin as Mr. De Witt

Brad Browne as Chief of Police

Elizabeth Flournoy as Miss Swithen (as Elizabeth Flourney)

Howard Banks as Policeman

Perc Launders as Fireman

Brad Johnson as Student

Billy Mauch as Student (as Bill Mauch)

Ann Tyrrell as Telephone Operator

Peggy as Bonzo