Nassau County, New York

county in New York, United States

Nassau County is a suburban county in the New York Metropolitan area east of New York City and west of Suffolk County, in the U.S. state of New York. In 2018, 1,358,343 people lived there. It lies in western Long Island, and is bordered by Suffolk County to the east and by the New York City boroughs of Brooklyn and Queens to the west. About 1,525,000 people lived there. Until 1899, Nassau County was part of Queens County. The county seat is Mineola. Along with Suffolk, it was named the safest county in the United States in 2005 by Forbes.

Nassau County
Hempstead House, part of Sands Point Preserve
Hempstead House, part of Sands Point Preserve
Flag of Nassau County
Map of New York highlighting Nassau County
Location within the U.S. state of New York
Map of the United States highlighting New York
New York's location within the U.S.
Coordinates: 40°44′50″N 73°38′17″W / 40.7472°N 73.6381°W / 40.7472; -73.6381
Country United States
State New York
Named forWilliam of Nassau
Largest villageHempstead
 • Total453 sq mi (1,170 km2)
 • Land285 sq mi (740 km2)
 • Water169 sq mi (440 km2)  37%
 • Estimate 
 • Density4,766.1/sq mi (1,840.2/km2)
Time zoneUTC−5 (Eastern)
 • Summer (DST)UTC−4 (EDT)
Congressional districts2nd, 3rd, 4th, 5th
Population is 2018 Census estimate.

Hamlets in Nassau County include Manhasset, New York.