Markus Herz (also Marcus Herz, German: [hɛɐ̯ts]; January 17, 1747 – January 19, 1803) was a German Jewish physician and lecturer on philosophy.
Born in Berlin to very poor parents, Herz was destined for a mercantile career, and in 1762 went to Königsberg, East Prussia. He soon gave up his position as clerk and attended the University of Königsberg, becoming a pupil of Kant, but was obliged to discontinue his studies for want of means. He thereupon became secretary to the wealthy Russian Ephraim, traveling with him through the Baltic Provinces. On August 21, 1770, he traveled from Berlin and acted as respondent when Kant presented his Inaugural dissertation at the University of Königsberg for the post of ordinary professor. In 1770 he had returned to Germany and studied medicine in Halle, where he became an MD in 1774, in which year he established himself in Berlin, being appointed physician at the Jewish hospital. Beginning in 1777, he delivered public lectures on medicine and philosophy, which were well attended by the students and the principal personages of the Prussian capital. At some of them even members of the royal family were present.