Ganga Bruta (literally "Brutal Gang"; also known as Rough Diamond) is a 1933 Brazilian drama film directed by Humberto Mauro. Starring Durval Bellini and Déa Selva, it follows a man who, after killing his wife on their wedding night, moves to a city where he becomes part of a love triangle. It was produced between 1931 and 1932 for Adhemar Gonzaga at his studio Cinédia.

On its initial release, the film was highly criticized and its poor viewing figures resulted in financial losses for the distribution company, but later critics and film directors expressed praise for it. Cinema Novo's Glauber Rocha considered it to be one of the best Brazilian films of all time, a title that would be recognized by the Brazilian Film Critics Association in 2015.