Hudson County is located in the U.S. state of New Jersey. It is part of the New Jersey Metropolitan Area. Hudson County is one of America's most ethnically diverse counties. Hudson County is the smallest of New Jersey's 21 counties.Hudson County has a total area of approximately 62 square miles of which 75% is land and 25% water. As of the 2000 census, there were 608,975 people, 230,546 households, and 143,630 families residing in Hudson County, NJ.