Hempstead is the most populous town in the U.S. state of New York. It is the largest of the three towns within Nassau County, and is located on Long Island, immediately east of southern Queens. The population was 793,409 at the time of the 2020 United States census, and its highest decennial census count ever was back in the 1970 United States census, where the town recorded a population of 801,592, which also made it the ninth largest municipality in the country by population at that time.