Immanuel Munk (30 May 1852, Posen – 1 August 1903, Berlin) was a German physiologist. He was the younger brother of physiologist Hermann Munk (1839–1912).
He studied medicine at the Universities of Berlin, Breslau and the Strasbourg, obtaining his doctorate in 1873 with the thesis Versuche über die Wirkung des Kryptopins. At Berlin, his influences included pharmacologist Oskar Liebreich and chemist Ernst Leopold Salkowski. In 1883 he began work as a lecturer in physiology and physiological chemistry, and from 1895, was an associate professor to the Faculty of Medicine in Berlin. In 1899 he attained a full professorship.
His research primarily dealt with issues pertaining to nutrition, metabolism, urinary secretions and the absorption/formation of animal body fat, to name a few. His scientific papers appeared mainly in "Virchows Archiv", "Pflüger's Archiv" and in the physiological division of the "Archiv für Anatomie und Physiologie". In 1897 he became editor of the periodical Centralblatt für Physiologie.