Ergy or Erzsy Landau (1896–1967) was a Hungarian-French humanist photographer. Born in Budapest, Landau worked in Franz Xaver Setzer's Vienna studio and then in Rudolf Dührkoop's studio in Berlin. She had photographed the German writer Thomas Mann and her painter/photographer friend, László Moholy-Nagy, whom she introduced to the medium. In May 1922 she emigrated to Paris, where she established herself as a portrait photographer. Landau brought the first Rolleiflex to France. Nora Dumas joined Landau's studio in 1929, and Ylla in 1932. Landau died in Paris.