The Framingham Heart Study is a long-term, ongoing cardiovascular cohort study of residents of the city of Framingham, Massachusetts. The study began in 1948 with 5,209 adult subjects from Framingham, and is now on its third generation of participants. Prior to the study almost nothing was known about the epidemiology of hypertensive or arteriosclerotic cardiovascular disease. Much of the now-common knowledge concerning heart disease, such as the effects of diet, exercise, and common medications such as aspirin, is based on this longitudinal study. It is a project of the National Heart, Lung, and Blood Institute, in collaboration with Boston University. Various health professionals from the hospitals and universities of Greater Boston staff the project.

Framingham is a city in the Commonwealth of Massachusetts, United States. Incorporated in 1700, it is located in Middlesex County and the MetroWest subregion of the Greater Boston metropolitan area. The city proper covers 25 square miles (65 km2) with a population of 72,362 in 2020, making it the 14th most populous municipality in Massachusetts. Residents voted in favor of adopting a charter to transition from a representative town meeting system to a mayor–council government in April 2017, and the municipality transitioned to city status on January 1, 2018. Before it transitioned, it had been the largest town by population in Massachusetts.