Darold A. Treffert (March 12, 1933 – December 14, 2020) was a psychiatrist and research director who specialized in the epidemiology of autism spectrum disorders and savant syndrome. He lived in Fond du Lac, Wisconsin. He was on the staff at Agnesian HealthCare and served on the Board of Trustees of Marian University. Treffert was a clinical professor at the University of Wisconsin Medical School. He was also a clinical professor at University of Wisconsin–Milwaukee.