thumb|right|250px|MMS headquarters in Waltham
The Massachusetts Medical Society (MMS) is the oldest continuously-operating state medical society in the United States. Incorporated on November 1, 1781, by an act of the Massachusetts General Court, the MMS is a non-profit organization that consists of approximately 22,000 physicians, medical students and residents. It is currently based in Waltham, Massachusetts. The majority of the members live or practice in Massachusetts and the immediate vicinity.

The Massachusetts Medical Society is the owner and publisher of the New England Journal of Medicine. It also publishes the Journal Watch family of professional newsletters.

In addition to its publishing activities, the key activities of the MMS include medical education for physicians, public health education for physicians and the public, legislative and regulatory advocacy for physicians and patients, and health policy research.
Officers:
Mario E. Motta, M.D. - President

Alice A. Tolbert Coombs, M.D., F.A.C.P. - President-Elect

Lynda Young, M.D., Vice President

Richard V. Aghababian, M.D., F.A.C.E.P. - Secretary-Treasurer

Deanna P. Ricker, M.D. - Assistant Secretary-Treasurer

Richard S. Pieters, M.D. - Speaker
Jesse Ehrenfeld, M.D., M.P.H. - Vice Speaker

Corinne Broderick - Executive Vice President, Massachusetts Medical Society