Suffolk County /ˈsʌfək/ is a suburban county on Long Island and the easternmost county in the U.S. state of New York. At the 2010 census, the county's population was 1,493,350, estimated to have increased to 1,502,968 in 2014, making it the fourth-most populous county in New York. Its county seat is Riverhead, though some county offices are located in Hauppauge.