Michael Caine
Harry Palmer
Nigel Green
Major Dalby
Guy Doleman
Colonel H.L. Ross
Sue Lloyd
Jean Courtney
Gordon Jackson
Jock Carswell
Aubrey Richards
Dr. Radcliffe
Frank Gatliff
Bluejay
Thomas Baptiste
Barney
Oliver MacGreevy
Housemartin
Freda Bamford
Alice
Pauline Winter
Charlady
Anthony Blackshaw
Edwards
Barry Raymond
Gray
David Glover
Chilcott-Oakes
Stanley Meadows
Inspector Pat Keightley
Peter Ashmore
Sir Robert
Mike Murray
Raid Inspector
Anthony Baird
Raid Sergeant
Tony Caunter
O.N.I Man
Charles Rea
Taylor
Ric Hutton
Records Officer
Douglas Blackwell
Murray
Richard Burrell
Operator
Glynn Edwards
Police Station Sergeant
Zsolt Vadaszffy
Prison Doctor
Josef Behrmann
Prison Guard
Max Faulkner
Prison Guard
Paul S. Chapman
Prison Guard
Richard Beale
Security Clerk (uncredited)
Victor Charrington
Security Guard (uncredited)
Michael Collins
R.S.M. (uncredited)
Howell Evans
First Agent (uncredited)
Peter Evans
Scientist (uncredited)
Victor Harrington
Audience Member at Symposium (uncredited)
George Holdcroft
Scientist (uncredited)
Pat Judge
Bluejay's Minder (uncredited)
Mollie Maureen
Tea Girl (uncredited)
Richard Neller
Scientist (uncredited)
Dido Plumb
Scientist (uncredited)
David Saire
Technician (uncredited)
Jack Sharp
Security Guard (uncredited)
George Spence
Scientist (uncredited)
William F. Sully
Bluejay's Minder (uncredited)
Harry Tierney
Scientist (uncredited)
Maggie Wright
Dalby's Staff (uncredited)