- Your Ad Here Nassau County is a suburban county in the New York Metropolitan Area east of New York City in the U.S. state of New York. As of the 2016 census, the population was 1,361,500. Nassau County's county seat is located in the Village of Garden City; however, it is within the Mineola, New York, 11501 ZIP Code. Therefore, the county seat is commonly referred to as being in Mineola. Sponsored Links History The name of the county comes from an old name for Long Island, which was at one time named Nassau, after Dutch 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. |