Oscar Baumann (25 June 1864 in Vienna – 12 October 1899 in Vienna) was an Austrian explorer, cartographer and ethnographer. He attended classes on natural history and geography at the University of Vienna, and in 1885 was part of an Austrian exploratory expedition of the Congo Basin under the direction of Oskar Lenz. However, because of serious illness, Baumann would be forced to leave the expedition prior to its conclusion. In 1886, he conducted ethnographical research on the island of Fernando Po. When he returned to Europe, he received his doctorate from the University of Leipzig (1888).