Brian Donlevy

Prof. Bernard Quatermass

John Longden

Chief Inspector Lomax

William Franklyn

Dr. Tom Brand

Bryan Forbes

Marsh

Charles Lloyd Pack

Work Camp Manager Dawson

Tom Chatto

Vincent Broadhead, M.P.

John Van Eyssen

The Plant Tour Guide

Sid James

Jimmy Hall

Percy Herbert

Paddy Gorman

Michael Ripper

Ernie the Bartender

John Rae

E. J. Macleod

Philipp Baird

Lab Assistant