Carl Ludwig, German physician and physiologist (b. 1815)
Carl Friedrich Wilhelm Ludwig (German: [ˈluːtvɪç]; 29 December 1816 – 23 April 1895) was a German physician and physiologist. His work as both a researcher and teacher had a major influence on the understanding, methods and apparatus used in almost all branches of physiology.

In 1842, Ludwig became a professor of physiology and in 1846 of comparative anatomy. From professorships in Zurich and Vienna he went in 1865 to the University of Leipzig and developed there the Physiological Institute, designated today after him: Carl Ludwig Institute of Physiology. Ludwig researched several topics such as the physiology of blood pressure, urinary excretion, and anesthesia. He received the Copley Medal in 1884 for his research. In 1869, he was elected a foreign member of the Royal Swedish Academy of Sciences. He is credited for inventing the stromuhr.

Since 1932, the Carl Ludwig Honorary Medal is awarded by the German Society for Cardiology to outstanding investigators in the area of cardiovascular research.