Franklin Square is a hamlet and census-designated place (CDP) in Nassau County, New York, United States. The population was 29,320 at the 2010 census. Franklin Square is an unincorporated area in the Town of Hempstead.
What is now Franklin Square was near the center of the Hempstead Plains, and used as grazing land, and later farmland, by the first white settlers. The southern portion included oak and dogwood forests.In late 1643, Robert Fordham and John Carman made a treaty with members of the Massapequak, Mericoke, Matinecock and Rockaway tribes to buy roughly 100 square miles upon which they intended to start a new settlement. They purchased this tract, including much of what are now the towns of Hempstead and North Hempstead. The source of the name "Franklin Square" is unclear. It has been speculated that the name honors Benjamin Franklin, but he had no historical connection to the area. It has been suggested that it was named for some now-forgotten local settler or notable.