The Hangman of London (German: Der Henker von London) is a 1963 West German mystery crime film directed by Edwin Zbonek and starring Hansjörg Felmy, Maria Perschy and Dieter Borsche. It is based on the novel The White Carpet by Bryan Edgar Wallace. The film was shot at the Spandau Studios in West Berlin and on location in London. The film's sets were designed by the art directors Hans Jürgen Kiebach and Ernst Schomer. It was produced at the same time as Rialto Film were enjoying great success with their series of films based on the works of Edgar Wallace, Bryan's father. It is also known by the alternative title The Mad Executioners, by which it was released by Paramount Pictures in the United States in 1965.
In London, police face two separate series of crimes. An underground "court" is trying and executing heinous criminals, while a deranged physician is murdering woman to assist his scientific experiments. Inspector Smith of Scotland Yard conducts the investigation into both killing sprees.