David Niven
— Alex Bolt
Virna Lisi
— Rhonda Bolt
Robert Vaughn
— Ray Whiteley
Ann Bell
— Pat Demarest
John Cleese
— Harry
Tim Brooke-Taylor
— Hillcrest
Hugh Burden
— Sir Geoffrey
Erik Chitty
— Mouser
Derek Francis
— Sanders
Susan Travers
— Mrs. Southwick
Desmond Walter-Ellis
— Mr. Southwick
David Allister
— Mr. Westbury
Maureen Lane
— Mrs. Westbury
Zoe Sallis
— Mrs. Euston
Graham Chapman
— News reader
Mario Guizzardi
— George French (uncredited)