Ergy or Erzsy Landau (1896–1967)[1] was a Hungarian-French humanist photographer.

She had photographed the German writer Thomas Mann and her painter/photographer friend, László Moholy-Nagy, whom she introduced to the medium.

Rado founded the photo press agency Rapho with Landau, Ylla, Brassaï, and Nora Dumas, but was forced to close the agency during World War II.

Landau had met Raymond Grosset [fr] on holiday in 1930, and introduced him to the other Hungarian photographers in Paris.

After World War II Landau encouraged Grosset to restart Rapho.