Kieron Moore

Cmdr. Michael Haydon

Lois Maxwell

Kim Hamilton

Donald Wolfit

Prof. Merrity

Bryan Forbes

Jimmy Wheeler

Jimmy Hanley

Larry Noble

Barry Keegan

Lefty

Walter Hudd

Professor Blandford

Donald Gray

Captain Ross

Thea Gregory

Barbara Noble

Shirley Lawrence

Ellen

Peter Neil

Tony

Ryck Rydon

Reporter

Ronan O'Casey

Reporter

Robert O'Neil

Reporter

Alan Gifford

Colonel Galloway

Charles Richardson

General Barnett

Carl Jaffe

Professor Bechstein

Leonard Sharp

Thomas the Watchman (uncredited)

Paul Beradi

Reporter (uncredited)

Patrick Halpin

Reporter (uncredited)

Terry Randall

Reporter (uncredited)

Bill Nagy

Reporter (uncredited)

Terry Randall

Reporter (uncredited)

John Wilder

Reporter (uncredited)

Johnny Wyne

Reporter (uncredited)

Trevor Reid

Simmons the Technician (uncredited)

Bernard Bresslaw

Technician (uncredited)

Alastair Hunter

Technician (uncredited)

Jane Dore

Young Girl (uncredited)

Frank Sieman

Gatekeeper (uncredited)

John Baker

Official (uncredited)

Tony Quinn

Jack the Barman

Tony Quinn

Jack the Barman (uncredited)