Duncan Gordon Sinclair CM (born November 2, 1933) is an American-born Canadian academic. He was inducted into the Canadian Medical Hall of Fame in 2015.^[1]

He was born in Rochester, New York,^[1] and received a DVM from the Ontario Veterinary College, an MSc from the University of Toronto and a PhD in physiology from Queen's University.^[2] From 1962-1963 he pursued post-doctoral medical research at Columbia University and from 1963 to 1965, he pursued post-doctoral medical research at St John's College, Cambridge. From 1974 to 1983, Sinclair was dean of the Faculty of Arts and Sciences at Queen's.^[1] He later served as vice-principal of Institutional Relations, vice-principal of services, vice-principal of Health Sciences and dean of the Faculty of Medicine;^[2] Sinclair was the first non-medical doctor to be chosen as head of a faculty of medicine in Canada.^[1] He retired from Queen's in 1996 but continues to be a guest lecturer at the University. In 1997, Queen's established the Dr. Duncan G. Sinclair Lectureship in Health Services and Policy Research,^[2]

In 1989, he was named an honorary fellow in the Royal College of Physicians and Surgeons of Canada.^[2]

Sinclair was chair of the Ontario Health Services Restructuring Commission and founding chair of Canada Health Infoway.^[3] He also served on the steering committee for the review by the Ontario Ministry of Health of the Public Hospitals Act .^[2]

Duncan G. Sinclair is the father of Gord Sinclair, bassist for The Tragically Hip.