Stephen M. Schwartz (January 1, 1942 – March 17, 2020) was an American pathologist. He worked at the University of Washington. He researched vascular biology, investigating the structure of blood vessels and smooth muscle cells. Schwartz was an assistant professor of pathology from 1974 to 1979, an associate professor from 1979 to 1984, and then a full professor from 1984 until his death.