Hermann Friedrich Oskar Kaul (11 October 1885 – 17 July 1968) was a German musicologist and professor at the University of Würzburg.
After elementary school he attended a Humanistisches Gymnasium in Cologne, then in 1905 he went to study music at the Hochschule für Musik und Tanz Köln there.
Among others, he was student of Max van de Sandt, Lazzaro Uzielli, Fritz Steinbach, Ewald Straeßer and Waldemar von Baußnern.
In 1908 he moved to the Hochschule für Musik und Theater München and studied musicology among others with Adolf Sandberger and Theodor Kroyer.
During this time, from 1942 to 1944, he was also active in the Würzburg music scene as V-Mann [de] of the Sicherheitsdienst des Reichsführers SS.