Robert Wise Director Michael Rennie Klaatu, Carpenter Actor Patricia Neal Helen Benson Actor Hugh Marlowe Tom Stevens Actor Sam Jaffe Prof. Jacob Barnhardt Actor Billy Gray Bobby Benson Actor Frances Bavier Mrs. Barley Actor Lock Martin Gort Actor Drew Pearson Self Frank Conroy Mr. Harley Actor Carleton Young Colonel in Jeep Actor Fay Roope Major General Actor Edith Evanson Mrs. Crockett Actor Robert Osterloh Major White Actor Tyler McVey Brady Actor John Brown George Barley (boarder) Actor Glenn Hardy Interviewer Actor House Peters Jr. Military Police Captain Actor H.V. Kaltenborn Self Harry Bates Writer Edmund H. North Writer Julian Blaustein Producer Bernard Herrmann Original Music Leo Tover Cinematographer William Reynolds Film Editing Addison Hehr Art Director Lyle R. Wheeler Art Director Claude E. Carpenter Set Decoration Thomas Little Set Decoration Perkins Bailey Costume Design Travilla Costume Design