Werner Stumm (1924 – 14 April 1999) was a Swiss chemist. After earning his doctorate in inorganic chemistry at the University of Zürich in 1952 he moved to the U.S. where he was active as a professor at Harvard University until 1969. From 1970 until 1992 he was head of the Swiss Federal Water Resources Centre EAWAG. Stumm is also known for writing the influential book Aquatic chemistry, together with James J. Morgan, and several other books on the interplay between mineral surfaces and water.