Nassau County /ˈnæsɔː/ is a suburban county on Long Island, immediately east of New York City in the U.S. state of New York, within the New York Metropolitan Area. As of the 2010 census, the population was 1,339,532. The name of the county comes from an old name for Long Island, which was at one time named Nassau, after the Dutch Prince William of Nassau, Prince of Orange (who later also ruled as King William III of England). The county colors (orange and blue) are also the colors of the House of Orange. Nassau's county seat is located in the village ofGarden City, within the Mineola 11501 zip code.[1][2] In 2012, Forbes magazine, in an article based on the U.S. Census Bureau's American Community Survey, reported that Nassau County was the 12th richest county in America and the wealthiest in the State of New York, with an annual median household income of about $91,000.[3]

Nassau, together with Suffolk County to its immediate east, are generally referred to as "Long Island" by area residents—as distinct from theNew York City boroughs of Queens (Queens County) and Brooklyn (Kings County), which are geographically located on the island's westernmost end. Two cities, three towns, 64 incorporated villages, and more than 60 unincorporated hamlets are located within the county. The U.S. Postal Service has organized Nassau County into 111 different 5-digit ZIP codes[4] served by 67 postal address names.[5] There are 56 public school districts within the county.[6] Post office districts and school districts use the same names as a city, hamlet, or village within them, but each sets the boundaries independently.[7]