Neal D. Barnard is an American physician, author, clinical researcher, and founding president of the Physicians Committee for Responsible Medicine (PCRM). An advocate of low-fat vegan diets, Barnard has written over a dozen books and published research papers on nutrition and its impact on human health. He has also conducted research into alternatives to animal experimentation and has been active in the animal rights movement. Barnard serves as president of The Cancer Project and heads the Washington Center for Clinical Research, a PCRM subsidiary.

Barnard grew up in Fargo, North Dakota in a family of cattle ranchers and physicians. He received his M.D. from George Washington University School of Medicine in Washington, D.C.

Barnard trained as a psychiatrist and is board certified by the American Board of Psychiatry and Neurology. For ten years he provided psychiatric services for the Calvary Shelter for Homeless Women in Washington, but then shifted his focus to research the impact of diet on human health, and towards finding alternatives to the use of animals in medical education, testing, and research. Barnard has published his research in academic journals including Lancet Oncology and the American Journal of Cardiology, and is an invited peer reviewer for the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health.