Michael Caine as Philip Kimberley / Sergei Kuzminsky

Laurence Olivier as Adm. Sir Gerald Scaith

Susan George as Penelope Kimberley / Annabelle Kimberley

Robert Powell as Jamie Fraser

Charles Gray as Sir James Chorley

Morteza Kazerouni as Boris Medvachian

Michael Medwin as Milroy

Eric Sevareid as Himself

Sabine Sun as Dr. Zilenka

David Kelly as Cameron

Patrick Dawson as Ginger

Vladek Sheybal as Gen. Zorin

Peter Burton as Douglas Ransom

Maggie Rennie as Mrs. Ransom

Richard Aylen as Older Kimberley

Anthony Pullen Shaw as Matthews

Maureen Bennett as Susan

Anthony Dawson as Vicar

Peggy Marshall as Polly

John Franklyn-Robbins as English doctor

Thomas Heathcote as Gamekeeper

Matthew Scurfield as KGB man #1

Robert Austin as KGB man #2

Jana Shelden as Air hostess

Peter Hutchins as Connolly

Yuri Borienko as Russian trainer

Bill Shine as Commissionaire

David Allister as Sgt. Lloyd

Jennifer Jayne as Nurse

Ian Masters as Special Branch Man

Richard Borthwick as Policeman

Owen Brenman as Policeman

Maurice Thorogood as Policeman

Nuala Barrie as Lady in Church

P.G. Stephens as Scaith's Driver

Nigel Humphreys as Petrol Attendant

Guy Standeven as Albert, The Club Steward (uncredited)