Brookville is a village located within the Town of Oyster Bay in Nassau County, on the North Shore of Long Island, in New York, United States. The population was 2,939 at the time of the 2020 census. The geographic Village of Brookville was formed in two stages. When the village was incorporated in 1931, it consisted of a long, narrow tract of land that …Brookville is a village located within the Town of Oyster Bay in Nassau County, on the North Shore of Long Island, in New York, United States. The population was 2,939 at the time of the 2020 census. The geographic Village of Brookville was formed in two stages. When the village was incorporated in 1931, it consisted of a long, narrow tract of land that was centered along Cedar Swamp Road. In the 1950s, the northern portion of the unincorporated area then known as Wheatley Hills was annexed and incorporated into the village, approximately doubling the village's area to its present 2,650 acres.