Warren County is a
county located in the
U.S. state of
New Jersey. As of the
2010 United States Census, the population was 108,692, having increased by 6,255 (+6.1%) from 102,437 counted at the
2000 Census, retaining its position as the 19th-most populous county in the state. Its
county seat is
Belvidere. It is part of the
Allentown-Bethlehem-Easton, PA-NJ metropolitan area and is generally considered the eastern border of the
Lehigh Valley, and also shares its western border with the
New York City Metropolitan Area, with its northwestern section bordering
The Poconos. The most populous place was
Phillipsburg, with 14,950 residents at the time of the 2010 Census, while
Hardwick Township, covered , the largest total area of any municipality.