Robin Phillips as Paul Pennyfeather

Michael Elwyn as Alastair Vane-Trumpington

Donald Wolfit as Dr. Augustus Fagan

Leo McKern as Captain Grimes

Geneviève Page as Margot Beste-Chetwynde

Felix Aylmer as Judge

Colin Blakely as Solomon Philbrick

Robert Harris as Prendergast

Griffith Jones as Sir Humphrey Maltravers

Patrick Magee as Maniac

Paul Rogers as Chief Warder

Donald Sinden as The Prison Governor

Rodney Bewes as Arthur Potts

Roland Curram as Otto Silenus

Patience Collier as Flossie Fagan

Jack Watson as Gallery Warder

Kenneth Griffith as Mr. Church

Helen Christie as Mrs. Clutterbuck

Michael Newport as Lord Tangent

Duncan Lamont as Inspector Bruce

Clifton Jones as Chokey

Joan Haythorne as Miss Hart

Jeremy Child as Nigel

John Cater as Blackall

Roy Beck as Public Schoolboy (uncredited)