Ben Peterson

James Whitmore*

Dr. Harold Medford

Edmund Gwenn

Dr. Patricia Medford

Joan Weldon

FBI Agent Robert Graham

James Arness

Brig. Gen. Robert O'Brien

Onslow Stevens

Maj. Kibbee

Sean McClory

Trooper Ed Blackburn

Chris Drake

The Ellinson Girl

Sandy Descher

Mrs. Lodge

Mary Ann Hokanson

Trooper Capt. Fred Edwards

Don Shelton

Alan Crotty

Fess Parker

Ambulance Attendant (uncredited)

William Schallert

Jensen

Olin Howlin

Air Force Sergeant (uncredited)

Leonard Nimoy

Jensen

Olin Howland

Railroad Yard Watchman

Dub Taylor

Child Psychiatrist

Ann Doran

Willis B. Bouchey

Dixon

Frederick J. Foote

Jerry

Robert Scott Correll

Bald Reporter at L.A. News Conference

Richard Deacon

Mike

Richard Bellis

Government Official

Forbes Murray

Ben's Driver

Joel Smith

Trooper #2

Kenner G. Kemp

Jeep Driver

Roydon E. Clark

Soldier

Charles Perry

Lab Man

Cliff Ferre

Gramps

Matthew McCue

Matron

Dorothy Green

Pilot

John Close

Coroner Putnam

Joe Forte

Official at D.C. Meeting

Willis Bouchey

Airman

Wally Duffy

Blonde at Police Station

Mary Lou Holloway

Attendant

Fred Shellac

Teenager in Police Station

Dick York

General

Norman Field

Admiral

Otis Garth

Dr. Grant

John Maxwell

WAVE

Janet Stewart

Cop

Dick Wessel

Coroner

Russell Gaige

Sutton

Robert Berger

Ryan

John Beradino

MP Sergeant

Dean Cromer

Engineer

Lawrence Dobkin

Loader

Chad Mallory

Gunner

Gayle Kellogg

Senator

Victor Sutherland

Radio Operator

Warren Mace

Army Officer

Jack Perrin

Doctor

Marshall Bradford

Doctor

Walden Boyle

Official

Alexander Campbell

Inmate

Harry Tyler

Inmate

Oscar Blanke

Officer

Eddie Dew

Officer

James Cardwell

Reporter

Walter Coy

Reporter

Booth Colman

Jeep Driver

Hubie Kerns

Ken Smith

Jeep Driver

Roydon Clark

Washington Official

Charles Meredith

Harry Wilson

Reporter

Douglas Spencer