Dyann F. Wirth (born Dyann Lynn Fergus, January 31, 1951, Racine, Wisconsin) is an American immunologist. She is currently the Richard Pearson Strong Professor of Infectious Diseases at Harvard T.H. Chan School of Public Health. Wirth is one of the world's leading malariologists, dealing with how the genus Plasmodium has evolved in terms of population biology, drug resistance, and antigenicity. The Wirth laboratory combines the expertise of the Harvard School of Public Health, the Broad Institute, and international collaborators for malaria research and training in public health.