The Town of Brookhaven is a town in Suffolk County on Long Island, New York, United States, it is the most populous of the ten towns in the county of Suffolk with a population of 485,773 at the 2020 U.S Census, Part of the New York metropolitan area, it is located approximately 50 miles from Manhattan. It is the largest of the state of New York's 932 towns by a…The Town of Brookhaven is a town in Suffolk County on Long Island, New York, United States, it is the most populous of the ten towns in the county of Suffolk with a population of 485,773 at the 2020 U.S Census, Part of the New York metropolitan area, it is located approximately 50 miles from Manhattan. It is the largest of the state of New York's 932 towns by area, and the second most populous after the Town of Hempstead in adjacent Nassau County.