Eddie Albert

Adm. Wiley Sloan

John Carradine

Ronald Bentley

Alex Cord

Dr. Sam Marlowe

Robert Forster

Comdr. Jeff Selkirk

Frank Gorshin

Dan Wesker

Mark Harmon

Peter Cabot

Christopher Lee

John McKenzie

Tom Dunstan

Agra Worker

Bruce Heighley

Technician

Robert Paul Jordan

(voice)

John Berwick

Crewman

Laurence Haddon

Cpt. Volero (uncredited)

Julie Bennett

Sylvia King

Michael White

PC18 Officer

Sandy Simpson

Moore

John Brandon

Chief Engineer (uncredited)

Clete Roberts

Newscaster (uncredited)

Kirk Cameron

Liam

Hedley Mattingly

Bailey

Peter Stader

Ed Linder (uncredited)

Lawrence Levine

(uncredited)

Michael Evans

Eric Whittaker

Alan Fudge

Lew Bascomb

Warwick Sims

Luke Crane

Lori Lethin

Maria (uncredited)

Laird Stuart

Paul (uncredited)

Peter von Zerneck

Hoffman

Kip Niven

Gantman (uncredited)

George Innes

Dave Winter

Belinda Mayne

Sally Crane

Duncan Regehr

Paul Ryker

Colin Drake

Old Man

Jean Marsh

Dr. Goldman

John McIntire

Sen. Oliver Bartholomew

Emma Samms

Lea McKenzie

Christina Nigra

Beth

Irene Hervey

Carrie (uncredited)

John Ratzenberger

Bill Sweeney

Lawrence Benedict

Young Bailey (uncredited)

Michael M. Vendrell

Robbie Cole (uncredited)

Tom Willett

Lambeth Walk Dancer (uncredited)

Jeanette Nolan

Sarah Bartholomew

Alan Caillou

Goliath Captain (uncredited)