Belmont is a town in Middlesex County, Massachusetts, United States. It is a western suburb of Boston, Massachusetts, United States; and is part of the Greater Boston metropolitan area. At the time of the 2020 U.S. Census, the town’s population stood at 27,295, up 10.4% from 2010.

Belmont was established on March 10, 1849, by former citizens of, and land from the bordering towns of Watertown, to the south; Waltham, to the west; and Arlington, then known as West Cambridge, to the north. They also wanted a town where no one could buy or sell alcohol (alcohol is now legal to purchase in Belmont). The town was named after Bellmont, the 200 acre (0.8 km) estate of the largest donor to its creation, John Perkins Cushing. Cushing Square is named after him and what was left of his estate after it nearly burned to the ground became a Belmont Public Library branch. The easternmost section of the town, including the western portion of Fresh Pond, was annexed by Cambridge in 1880 in a dispute over a slaughterhouse licensed in 1878 on Fresh Pond, so that Cambridge could protect Fresh Pond, a part of its municipal water system.^{[citation needed]}

Preceding its incorporation, Belmont was an agrarian based town, with several large farms servicing Boston for produce and livestock. It remained largely the same until the turn of the twentieth century, when trolley service and better roads were introduced, making the town more attractive as a residential area, most notably for the building of large estates. Belmont’s population grew by over 70 percent during the 1920s.

The economics of the town shifted from purely agrarian to a commercial greenhouse base; much of the flower and vegetable needs of Boston were met from the Belmont ‘hothouses’ which persisted until about 1983 when Edgar’s, the last large greenhouse firm in the area, closed.

Other commercial enterprises in Belmont included mining clay and waste management. The reclamation of a large dump and quarry off Concord Avenue into sites for the Belmont High School and the Clay Pit Pond stands as a lasting example of environmental planning. With the introduction of automobiles and highways, Belmont continued its transition to a commuter-based suburb throughout the twentieth century.

Belmont was the home of the headquarters of the John Birch Society from the organization’s founding in 1958 until its relocation to Appleton, Wisconsin in 1989. The building at 395 Concord Avenue later became the headquarters of the National Association for Armenian Studies and Research (NAASR), which is expanding and renovating its facility as of 2019.