Gene Barry
Dr. Clayton Forrester
Ann Robinson
Sylvia Van Buren
Lewis Martin
Pastor Dr. Matthew Collins
Les Tremayne
Maj. Gen. Mann
Frank Kreig
Fiddler Hawkins (uncredited)
Vernon Rich
Col. Ralph Heffner
Sandro Giglio
Dr. Bilderbeck
Ann Codee
Dr. Duprey (uncredited)
Robert Cornthwaite
Dr. Pryor (as Bob Cornthwaite)
Cedric Hardwicke
Commentary (voice) (as Sir Cedric Hardwicke)
William Phipps
Wash Perry (as Bill Phipps)
Jack Kruschen
Salvatore
Paul Birch
Alonzo Hogue (uncredited)
Paul Frees
Second Radio Reporter / Opening Announcer
Henry Brandon
Cop at Crash Site
Peter Adams
Pine Summit Fire Watcher (uncredited)
Eric Alden
Man (uncredited)
Edgar Barrier
Prof. McPherson (uncredited)
Russ Bender
Dr. Carmichael (uncredited)
Chet Brandenburg
Man in Church (uncredited)
Edward Colmans
Spanish Priest (uncredited)
Russ Conway
Rev. Bethany (uncredited)
Pierre Cressoy
Frenchman (uncredited)
Ralph Dumke
Buck Monahan (uncredited)
Al Ferguson
Police Chief (uncredited)
Charles Gemora
Martian (uncredited)
Ned Glass
Well-Dressed Looter (uncredited)
Fred Graham
Looter (uncredited)
Herman Hack
Worker Listening to Radio (uncredited)
Nancy Hale
Young Wife (uncredited)
Ted Hecht
KGEB Reporter (uncredited)
Douglas Henderson
Staff Sergeant (uncredited)
Gertrude Hoffmann
Elderly News Vendor (uncredited)
Dick Johnstone
Man in Church (uncredited)
Carolyn Jones
Blonde Party Guest (uncredited)
Ivan Lebedeff
Dr. Gratzman (uncredited)
Freeman Lusk
Secretary of Defense (uncredited)
Herbert Lytton
Chief of Staff (uncredited)
Wilbur Mack
Official (uncredited)
George Magrill
Traffic Cop (uncredited)
Joel Marston
Military Policeman in Jeep (uncredited)
John Maxwell
Doctor (uncredited)
David McMahon
Minister, First Church (uncredited)
Lee Miller
Reporter (uncredited)
Alvy Moore
Zippy (uncredited)
Bob Morgan
Injured Civil Defense Worker (uncredited)
Charles Morton
Worker Listening to Radio (uncredited)
George Pal
Bum #1 Listening to Radio (uncredited)
Robert Rockwell
Forest Ranger at Crash Site (uncredited)
Walter Sande
Sheriff Bogany (uncredited)
James Seay
Air Force Bomber Pilot (uncredited)
David Sharpe
Looter (uncredited)
Teru Shimada
Japanese Diplomat (uncredited)
Bert Stevens
Man in Church (uncredited)
Jack Stoney
Looter (uncredited)
Arthur Tovey
Party Guest (uncredited)
Dale Van Sickel
Looter (uncredited)
Dorothy Vernon
Elderly Woman at Square Dance (uncredited)
Anthony Warde
Military Police Driver (uncredited)
Houseley Stevenson Jr.
Gen. Mann's Aide (as Housely Stevenson Jr.)
Hugh Allen
Brigadier General (uncredited)
Ruth Barnell
Mother (uncredited)
Oscar Blank
Man in Church (uncredited)
Hazel Boyne
Screaming Woman (uncredited)
George Bruggeman
Soldier (uncredited)
Nora Bush
Woman in Church (uncredited)
Tony Butala
Boy in Final Church (uncredited)
Mushy Callahan
Burning Soldier at Pit (uncredited)
Dick Cherney
Looter (uncredited)
James Conaty
Man at Pacific Institute of Science and Technology (uncredited)
Martin Coulter
Marine Sergeant (uncredited)
Vittorio Cramer
First Radio Reporter (uncredited)
Oliver Cross
Scientist (uncredited)
Jane Crowley
Woman in Church (uncredited)
Jim Davies
Marine Commanding Officer (uncredited)
Helen Dickson
Woman in Church (uncredited)
Jimmie Dundee
Civil Defense Official (uncredited)
Dick Fortune
Marine Captain (uncredited)
Alex Frazer
Dr. James (uncredited)
Frank Freeman Jr.
Bum #2 Listening to Radio (uncredited)
Slim Gaut
Radio Listener (uncredited)
Jack Gordon
Man in Church (uncredited)
Joe Gray
Looter (uncredited)
Virginia Hall
Girl (uncredited)
Tex Holden
Man in Church (uncredited)
Jimmie Horan
Party Guest (uncredited)
Patricia Iannone
Girl (uncredited)
Jerry James
Reporter (uncredited)
Michael Jeffers
Worker Listening to Radio (uncredited)
Don Kohler
Colonel (uncredited)
Mike Mahoney
Townsman (uncredited)
John Mansfield
Man (uncredited)
Sydney Mason
Fire Chief, Crew #3 (uncredited)
Mathew McCue
Man in Church (uncredited)
William Meader
P.E. Official (uncredited)
Ralph Montgomery
Los Angeles Red Cross Official (uncredited)
George Nardelli
Military Officer (uncredited)
Stanley Orr
Marine Major (uncredited)
Walter Richards
Reporter (uncredited)
Allen D. Sewall
Man in Church (uncredited)
Lucile Sewall
Woman in Church (uncredited)
Cora Shannon
Old Woman (uncredited)
Reginald Lal Singh
Military Officer (uncredited)
Bobby Somers
Deputy at Crash Site (uncredited)
Charles Stewart
Marine Captain (uncredited)
Gus Taillon
Elderly Man (uncredited)
Morton C. Thompson
Reporter (uncredited)
Edward Wahrman
Cameraman (uncredited)
Bob Whitney
Military Officer (uncredited)
Chalky Williams
Worker Listening to Radio (uncredited)
Waldon Williams
Boy (uncredited)
Bud Wolfe
Rescuing Civil Defense Worker (uncredited)
Fred Zendar
Marine Lieutenant (uncredited)