Eduard Ott-Heinrich Keller (1906-1990) was a German mathematician who worked in the fields of geometry, topology and algebraic geometry. He formulated the celebrated problem which is now called the Jacobian conjecture in 1939. He was born in Frankfurt am-Main, and studied at the universities of Frankfurt, Vienna, Berlin and Göttingen. As a student of Max Dehn he wrote a dissertation on the tiling of space with cubes. This led to another 'Keller conjecture': the Keller cube-tiling conjecture from 1930. This was shown to be true in dimensions at most 6 by Oskar Perron in 1940, and to be false in dimensions at least 10 by Jeffrey Lagarias and Peter Shor in 1992. The related Minkowski lattice cube-tiling conjecture was proved by György Hajós in 1942.