Calvin O. Qualset, often known as Cal Qualset, is an American agricultural scientist specializing in plant genetics, crop breeding, and conservation of genetic resources. He worked for many years at the University of California, Davis, where he became a professor of agronomy and range science and later Professor Emeritus. He served as Director of the UC Genetic Resources Conservation Program, focusing on the preservation of plant genetic diversity and the improvement of important crops such as wheat, oats, and triticale.