Peter Sellers as The Rev. John Smallwood

Cecil Parker as Archdeacon Aspinall

Isabel Jeans as Lady Despard

Ian Carmichael as The Other Smallwood

Bernard Miles as Simpson

Brock Peters as Matthew Robinson

Eric Sykes as Harry Smith

Irene Handl as Rene Smith

Miriam Karlin as Winnie Smith

Joan Miller as Mrs Smith-Gould

William Hartnell as Major Fowler

Roy Kinnear as Fred Smith

John Harvey as Wilson, Prison Officer

Joan Hickson as Housewife

Eric Barker as Bank Manager

John Comer as Butcher

Kenneth Griffith as Rev. Owen Thomas

Mark Eden as Sir Geoffrey Despard

Basil Dignam as Prison Governor

Colin Gordon as Prime Minister

Geoffrey Hibbert as Council Official

Ludovic Kennedy as Himself

Malcolm Muggeridge as Cleric

Harry Locke as Shop Steward

Derek Nimmo as DG Assistant

Conrad Phillips as Deaf Man

Miles Malleson as Bishop Rockeby

Nicholas Phipps as DG

Thorley Walters as Tranquilax Executive

Marianne Stone as Miss Palmer

Cardew Robinson as Tramp

Gerald Sim as Store Manager

Anna Wing as Housewife (uncredited)

John Junkin as Reporter at Space Launch Site (uncredited)

Rodney Bewes as Milkfloat Driver (uncredited)

Steve Marriott as Jack (uncredited)

Louis Mansi as Man Buying Groceries (uncredited)

Jack Carter as Launch Site Worker (uncredited)