The Massachusetts General Court, formally the General Court of Massachusetts, is the state legislature of the Commonwealth of Massachusetts located in the state capital of Boston. The name "General Court" is a holdover from the earliest days of the Massachusetts Bay Colony, when the colonial assembly, in addition to making laws, sat as a judicial court of appeals. Before the adoption of the state constitution in 1780, it was called the Great and General Court, but the official title was shortened by John Adams, author of the state constitution. It is a bicameral body. The upper house is the Massachusetts Senate which is composed of 40 members. The lower body, the Massachusetts House of Representatives, has 160 members; until 1978, the state house had 240 members. It meets in the Massachusetts State House on Beacon Hill in Boston.

The Massachusetts Charter of 1691 was a charter that formally established the Province of Massachusetts Bay. Issued by the government of William III and Mary II, the corulers of the Kingdom of England, the charter defined the government of the colony, whose lands were drawn from those previously belonging to the Massachusetts Bay Colony, Plymouth Colony, and portions of the Province of New York. The territorial claims embodied in the charter also encompassed all of present-day Maine, New Brunswick, and Nova Scotia.