Robert Abraham Esau (7 June 1884 – 12 May 1955) was a German physicist. After receipt of his doctorate from the University of Berlin, Esau worked at Telefunken, where he pioneered very high frequency (VHF) waves used in radar, radio, and television, and he was president of the Deutscher Telefunken Verband. During World War I, he was a prisoner of war of the French; he was repatriated to Germany in 1919. In 1925, he was appointed professor at the University of Jena, where he also served as rector. From 1933, Esau was the State Councilor in Thuringia.