Gustav Hauser (13 July 1856 in Nördlingen – 30 June 1935 in Erlangen) was a German pathologist and bacteriologist. He studied medicine at the Universities of Munich and Erlangen, where he worked as an assistant in the gynecological clinic under Paul Zweifel and at the pathological institute of Friedrich Albert von Zenker. In 1883 he obtained his habilitation for pathological anatomy and bacteriology, and in 1895 became a full professor and director of the institute of pathology in Erlangen. In Erlangen, the thoroughfare Gustav-Hauser-Straße is named in his honor.