Michael Rennie

Klaatu / Mr. Carpenter

Patricia Neal

Helen Benson

Billy Gray

Bobby Benson

Sam Jaffe

Prof. Jacob Barnhardt

Hugh Marlowe

Tom Stevens

Lock Martin

Gort

Freeman Lusk

General Cutler

Edith Evanson

Mrs. Crockett

Frank Conroy

Mr. Harley

Frances Bavier

Mrs. Barley

John Brown

George Barley

Olan Soule

Mr. Krull