Rudolf Kraus (31 October 1868, Jungbunzlau – 15 July 1932) was an Austrian pathologist, bacteriologist and immunologist known for his work with bacterial precipitins. In 1893 he obtained his doctorate at the University of Prague. Following studies at the Pasteur Institute in Paris, he settled in Vienna in 1895 as an assistant to Richard Paltauf (1858-1924) at the serotherapeutic institute. In 1901 he became a privat-docent for general and experimental pathology, followed by a promotion as associate professor in 1906. In 1908 he traveled to St. Petersburg, where he conducted investigations of an epidemic of cholera.