Uniondale is a hamlet (and census-designated place) as well as a suburb of New York City in Nassau County, New York, United States, on Long Island, in the Town of Hempstead. The population was 23,011 at the 2000 United States Census.
Uniondale is located at 40°42′11″N 73°35′28″W / 40.70306°N 73.59111°W / 40.70306; -73.59111 (40.703097, -73.591070).
According to the United States Census Bureau, the village has a total area of 2.7 square miles (6.9 km²), all land. It is a diverse hamlet and neighbors the diverse towns of Hempstead, Roosevelt, Freeport, and East Meadow.