Ernst August Max Friedrich Rump (13 October 1872, Hamburg - 12 January 1921, Hamburg) was a German merchant, art patron and collector. In 1912, he wrote the Lexikon der bildenden Künstler Hamburgs, Altonas und der näheren Umgebung (Encyclopedia of Visual Artists from Hamburg, Altonas and the Surrounding Area), which became a classic; generally referred to as Der Rump.