August Potthast (13 August 1824, Höxter, Province of Westphalia – 13 February 1898, Leobschütz), was a German historian, was born at Höxter, and was educated at Paderborn, Münster and Berlin. He assisted GH Pertz, the editor of the Monumenta Germaniae Historica, and edited the Regesta pontificum romanorum, 1198-1304 (Berlin, 1874–1875). From 1874 to 1894 he was librarian of the German Reichstag.