Julius Wolfgang Weichardt (13 May 1875 – 1943) was a German bacteriologist who was a native of Altenburg, Thüringen. In 1900 he received his doctorate at Breslau, where he became an assistant to Carl Flügge (1847-1923) at the laboratory for hygiene and bacteriology. Afterwards he was an assistant in Dresden under pathologist Christian Georg Schmorl (1861-1932), in Paris at the Pasteur Institute under Ilya Ilyich Mechnikov (1845-1916), in Hamburg under American-born hygienist William Philipps Dunbar (1863-1922), and at the Berlin institute of hygiene under Max Rubner (1854-1932).