Heinrich Anton de Bary (26 January 1831 - 19 January 1888) was a German surgeon, botanist, microbiologist, and mycologist (fungal systematics and physiology).
He is considered a founding father of plant pathology (phytopathology) as well as the founder of modern mycology. His extensive and careful studies of the life history of fungi and contribution to the understanding of algae and higher plants established landmarks in biology.
Born in Frankfurt to physician August Theodor de Bary (1802–1873) and Emilie Meyer de Bary, Anton de Bary was one of ten children. He joined excursions of naturalists who collected local specimens. De Bary’s interest was further inspired by George Fresenius, a physician, who also taught botany at Senckenberg Institute. Fresenius was an expert on thallophytes. In 1848, de Bary graduated from a gymnasium at Frankfurt, and began to study medicine at Heidelberg, continuing at Marburg. In 1850, he went to Berlin to continue pursuing his study of medicine, and also continued to explore and develop his interest in plant science. Although he received his degree in medicine, his dissertation at Berlin in 1853 was titled "De plantarum generatione sexuali", a botanical subject. He also published a book on fungi and the causes of rusts and smuts.
After graduation, de Bary briefly practiced medicine in Frankfurt, but he was drawn back to botany and became Privatdozent in botany at the University of Tübingen, where he worked for a while as an assistant to Hugo von Mohl (1805–1872). In 1855, he succeeded the botanist Karl Wilhelm von Nägeli (1818–1891) at Freiburg, where he established the most advanced botanical laboratory at the time and directed many students.
In 1867, de Bary moved to the University of Halle as successor to Professor Diederich Franz Leonhard von Schlechtendal, who, with Hugo von Mohl, co-founded the pioneer botanical journal Botanische Zeitung. De Bary became its coeditor and later sole editor. As an editor of and contributor to the journal, he exercised great influence upon the development of botany.