The Mystery of Betty Bonn (German: Das Geheimnis um Betty Bonn) is a 1938 German adventure film directed by Robert A. Stemmle and starring Maria Andergast, Theodor Loos and Hans Nielsen. The film was shot at the Babelsberg Studios in Berlin with sets designed by the art directors Wilhelm Depenau and Ludwig Reiber. It was made by the leading German company UFA, based on a novel by Friedrich Lindemann.