Dr. Kelly is the Elizabeth R. Spallin Professor of Psychiatry in Addiction Medicine at Harvard Medical School – the first endowed professor in addiction medicine at Harvard. He is also the Founder and Director of the Recovery Research Institute at the Massachusetts General Hospital (MGH) and the National Center on Youth Prevention, Treatment, and Recovery at MGH. He also serves as the Chief of the Division of Addiction Treatment and Prevention across the Mass General Brigham (MGB) Academic Medical Centers (AMC) Department of Psychiatry (AMC Psychiatry).

Dr. Kelly is a former President of the American Psychological Association's (APA) Society of Addiction Psychology, a founding member and inaugural President of the American Board of Addiction Psychology, a Fellow of the APA, and a Diplomate of the American Board of Professional Psychology. He has served as a consultant to U.S. federal agencies and non-federal institutions, as well as foreign governments, the United Nations and the World Health Organization.

Dr. Kelly has published over 300 peer-reviewed articles, reviews, chapters, and books in the field of addiction medicine, and was an author on the U.S. Surgeon General's Report on Alcohol, Drugs, and Health. He has won numerous state, national, and international lifetime achievements and distinguished scientist awards for his work.

His clinical and research endeavors have focused on addiction treatment and the recovery process, mechanisms of behavior change, and reducing stigma and discrimination among individuals suffering from addiction.