Emil Osann (May 25, 1787 – January 11, 1842) was a German physician and physiologist from Weimar. He is the father of balneology. He studied medicine in Jena and Göttingen, and later was an assistant to his uncle, Christoph Wilhelm Hufeland (1762–1836) at the latter's policlinic in Berlin. In 1833 he became director of Hufeland's outpatient clinic.
Osann is remembered for his work on the effects of mineral springs from a medical and physiological standpoint. Among his written works was Physikalisch-medicinische Darstellung der bekannten Heilquellen der vorzüglichsten Länder Europas, which was a two-volume publication about European mineral spas. It is considered to be the first comprehensive work of balneology. In 1837 he became editor of the Journal der praktischen Heilkunde (Journal of Practical Medicine).