Peter McCullough was born in Buffalo, New York, on 29 December 1962. When a teenager, his family moved to Texas (Wichita Falls and later to Grapevine). He graduated from Baylor University in May 1984 and from the University of Texas Southwestern Medical School in June 1988. His residency in internal medicine was at the University of Washington School of Medicine in Seattle, Washington. Upon completion of his 3 years training in June 1991, he moved to Grayling, Michigan, and served as an internal medicine attending at Mercy Hospital for 2 years.