Morris County is a county located in the U.S. state of New Jersey, about 50 mi (80 km) west of New York City. According to the 2010 census, the population was 492,276 up from the 470,212 at the 2000 Census As of the 2017 Census estimate, the county's population was 499,693, making it the state's 10th-most populous county, and marking a 1.5% increase from 2010 The county is part of the New York Metropolitan Area, and its county seat is Morristown. The most populous place was Parsippany-Troy Hills Township, with 53,238 residents at the time of the 2010 Census, while Rockaway Township covered 45.55 square miles, the largest total area of any municipality.