Nassau County is a suburban county located on Long Island, immediately to the east of New York City. As of the 2020 United States census, Nassau County's population was 1,395,774 with one police department, making it the sixth-most populous county in the State of New York, and reflecting an increase of 56,242 from the 1,339,532 residents enumerated at the 2010 census. Its county seat is Mineola, while the county's largest town is Hempstead.