Braintree, town (township), Norfolk county, eastern Massachusetts, U.S. It lies along Weymouth Fore River (an inlet of Hingham Bay), just southeast of Boston. It was settled in 1634 as Monoticut (an Algonquian word meaning “abundance”) and was part of Boston until it was separately incorporated in 1640 and named for Braintree in Essex, England. At that time, the town included the areas of present-day Randolph, Holbrook, Quincy, and parts of Milton. To obtain a clear title, the town purchased its land from Native Americans in 1665. Ironworks, using local bog iron, were established there as early as 1643, and glassmaking began in 1752. Factories built during the 18th and 19th centuries produced a wide variety of products, including chocolate, textiles, and hardware. Most employment in the area is now based on services and trade, although manufacturing remains important.
The statesman John Hancock and Presidents John Adams and John Quincy Adams were born in a section of the town that was separately incorporated as Quincy in 1792. The General Sylvanus Thayer Birthplace is a restored 18th-century home in Braintree. The village of South Braintree (within the township) was the scene of the payroll robbery murders that led to the Sacco-Vanzetti trial of 1920–27. Area 15 square miles (39 square km). Pop. (2000) 33,828; (2010) 35,744.