Quatermass
Lomax (as John Longdon)
Jimmy Hall (as Sydney James)
Marsh
Brand
Sheila
Dawson
Broadhead
The P.R.O.
Gorman
Ernie
McLeod
Secretary
Young Man
Mrs. McLeod
Kelly
Inspector
Commissioner
Banker
Woman M.P.
Peterson
Michaels
Lab. Assistant (as Philip Baird)
Lab. Assistant
Intern
Super
Constable
Harry
Policeman (uncredited)
Worker (uncredited)
Guard (uncredited)
First Man (uncredited)
Young Girl (uncredited)
Labour MP (uncredited)
Chris (uncredited)
VIP at Research Plant (uncredited)
Police Sergeant Escorting Suspect (uncredited)
Police Sergeant (uncredited)
Intern (uncredited)
Drunk (uncredited)
Woman Shopper (uncredited)