Belmont, town, Middlesex County, eastern Massachusetts; incorporated 1859. It developed as a residential suburb after a rapid transit line to nearby Boston was completed in 1912. Settled in the 1630s as the Pequosette Plantation, the community was set off in 1859 from parts of Watertown, Waltham, and West Cambridge (now Arlington). Belmont grew as a farming and summer community and was named for a local estate. Population 26,100 (1980); 24,720 (1990); 24,720 (1996 estimate).
