Admiral Harriman Nelson

Walter Pidgeon

Captain Lee Crane

Robert Sterling

Dr. Susan Hiller

Joan Fontaine

Lieutenant Cathy Conners

Barbara Eden

Comm. Lucius Emery

Peter Lorre

Miguel Alvarez

Michael Ansara

Lt (j.g.) Danny Romano

Frankie Avalon

Dr. Jamieson

Regis Toomey

Vice Admiral B.J. Crawford

John Litel

Congressman Llewellyn Parker

Howard McNear

Dr. Zucco

Henry Daniell

Seaman Jimmy "Red" Smith

Mark Slade

Sparks

Robert Easton

CPO Gleason

Charles Tannen

Seaman Kowski

Delbert Monroe

Cookie

Anthony Monaco

Seaman George Young

Jonathan Gilmore

Ned Thompson

David McLean

Crew member

Skip Ward

Crew member

Michael Ford

Dr. Newmar

Larry Gray

Dr. Newmar

Larry Grey

Lieutenant Hodges (Uncredited)

George Diestel

Crew Member (Uncredited)

William Herrin

Crew Member (Uncredited)

Robert Buckingham

Crew Member (Uncredited)

Richard Adams

Crew Member (Uncredited)

Jimmy Murphy

UN Commentator

Art Baker

UN Chairman

Kendrick Huxham

Delegate (Uncredited)

John Giovanni

Crew Member

Michael D. Ford

Dr. Newmar

Lawrence Gray [act]

Officer (Uncredited)

Edward Rickard

Seaview Pilot (Uncredited)

Charles Dierkop

Guard (Uncredited)

Rodger Terry

Guard (Uncredited)

Brad Brown

Delegate (Uncredited)

Raoul Freeman

Delegate (Uncredited)

Al Bain

Delegate (Uncredited)

Harry Baum

Delegate (Uncredited)

Benjie Bancroft

Delegate (Uncredited)

Michael Cirillo

Delegate (Uncredited)

Harry Denny

Delegate (Uncredited)

Bhupesh Guha

Delegate (Uncredited)

Esther Ying Lee

Delegate (Uncredited)

Robert Locke Lorraine

Delegate (Uncredited)

George Nardelli

Delegate (Uncredited)

Paul Power

Delegate (Uncredited)

Paul Ravel

Delegate (Uncredited)

Scott Seaton

Delegate (Uncredited)

Leslie Sketchley

Delegate (Uncredited)

Ray Spiker

Delegate (Uncredited)

Hal Taggart

Delegate (Uncredited)

Robert Strong

Crew Member (uncredited)

Ron Nyman