Markus Herz (also Marcus Herz, German: [hɛɐ̯ts]; January 17, 1747 – January 19, 1803) was a German Jewish physician and lecturer on philosophy. Herz was a friend and pupil of Moses Mendelssohn, and was also well acquainted with Gotthold Lessing. He tutored, Alexander von Humboldt. For many years, Herz corresponded with Emmanuel Kant and their letters are considered to be of philosophical importance.