The Town of Braintree is a municipality in Norfolk County, Massachusetts, United States. Although officially known as a town, Braintree adopted a municipal charter, effective 2008, with a mayor-council form of government and is considered a city under Massachusetts law. The population was 33,828 at the 2000 census. It is part of the Greater Boston area with access to the MBTA Red Line and is a member of the Metropolitan Area Planning Commission's South Shore Coalition. The first and current mayor of Braintree is Joe Sullivan.