Plainsboro Township is a township in Middlesex County in the U.S. state of New Jersey. The township is centrally located in the Raritan Valley region and is a part of the New York metropolitan area. As of the 2010 United States Census, the township's population was 22,999, reflecting an increase of 2,784 (+13.8%) from the 20,215 counted in the 2000 Census, which had in turn increased by 6,002 (+42.2%) from the 14,213 counted in the 1990 Census.
