Wilhelm Kolle (born 2 November 1868 in Lerbach near Osterode am Harz, died 10 May 1935) was a German bacteriologist and hygienist. He served as the second director of the Royal Institute for Experimental Therapy, succeeding its founder, the Nobel laureate Paul Ehrlich. He was also the original author, with Heinrich Hetsch, of the famous book Experimental Bacteriology, one of the most authoritative works in microbiology in the first half of the 20th century.
Following studies of medicine at the universities of Göttingen, Halle and Würzburg, he became an assistant to Robert Koch at the Institut für Infektionskrankheiten (Institute for Infectious Diseases) in Berlin (1893–97). In 1897–98 he performed research of rinderpest and leprosy in South Africa, and in 1900, on behalf of the Egyptian government, studied rinderpest in Sudan.
In 1901 he became departmental head at the Institut für Infektionskrankheiten, followed by an appointment as professor of hygiene and bacteriology at the University of Bern (1906). As a military physician and hygienist during World War I, he was highly successful in vaccination against diphtheria and cholera. In 1917, he became director of the Royal Institute for Experimental Therapy and of the Georg Speyer House in Frankfurt am Main.