Nassau County is a suburban county located on Long Island, immediately to the east of New York City, bordering the Long Island Sound on the north and the open Atlantic Ocean to the south. As of the 2020 United States census, Nassau County's population was 1,395,774, making it the sixth-most populous county in the State of New York, and reflecting an increase of 56,242 (+4.2%) from the 1,339,532 residents enumerated at the 2010 census. Its county seat is Mineola, while the county's largest and most populous town is Hempstead.