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