Donald L. Showalter is a professor emeritus and former chairman of the Department of Chemistry at the University of Wisconsin–Stevens Point.
Born in Louisville, Kentucky, Showalter received his bachelors degree from Eastern Kentucky University in 1964 and his Ph.D. in 1970 from the University of Kentucky. He spent one year as a research fellow at Oregon State University's Radiation Center before moving to UWSP in 1971. For a brief time (1973–1976) he taught at Iowa Western Community College before returning to UWSP, where he would receive many teaching awards, such as the University of Wisconsin Board of Regents Excellence in Teaching Award in 1994. In September 2006 he won Helen M. Free Award for Public Outreach.
Showalter stars in The World of Chemistry video series with Roald Hoffmann.