Michael Rennie
character Klaatu, alias Mr. Carpenter
Patricia Neal
character Helen Benson
Billy Gray
character Bobby Benson
Sam Jaffe
character Prof. Jacob Barnhardt
Hugh Marlowe
character Tom Stevens
Lock Martin
character Gort
Freeman Lusk
character General Cutler
Edith Evanson
character Mrs. Crockett, landlady
Frank Conroy
character Mr. Harley, Secretary to the President
Frances Bavier
character Mrs. Barley, boarder
John Brown
character George Barley, boarder
Olan Soule
character Mr. Krull, boarder
Marjorie Crossland
character Hilda, Barnhart's secretary
Elmer Davis
character Elmer Davis
H.V. Kaltenborn
character H. V. Kaltenborn
Drew Pearson
character Drew Pearson
Gabriel Heatter
character Gabriel Heatter (voice)
Harry Lauter
character Lieutenant in Charge of Landing Site
James Doyle
character Army Dr. White
Larry Dobkin
character Balding Army Doctor
Robert Osterloh
character Army Examining Doctor
Glenn Hardy
character Radio Interviewer at Landing Site
Tyler McVey
character Brady
House Peters Jr.
character M.P. Captain at Barnhardt's
George Lynn
character Conference Colonel Ryder
Dorothy Neumann
character Margaret, Tom's secretary
Wheaton Chambers
character Mr. Bleeker, jeweller
Carleton Young
character Zone Five Lieutenant Colonel
Harry Harvey
character The Cab Driver
Sammy Ogg
character Sammy, boy witness
Bess Flowers
character Lady Outside Jewelry Store
James Seay
character Government Man
Grady Galloway
character Radar Operator
Hassan Khayyam
character Indian Newscaster
John Barton
character British Newscaster
Stuart Whitman
character Sentry (scene deleted)
