Manhasset is a hamlet and census-designated place in Nassau County, on the North Shore of Long Island, in New York, United States. It is considered the anchor community of the Greater Manhasset area. The population was 8,176 at the 2020 census. As with other unincorporated communities in New York, its local affairs are administered by the town in which it is located, the Town of North Hempstead, whose town hall is in Manhasset, making the hamlet the town seat.