Parsippany-Troy Hills Township, commonly called Parsippany, is a township in Morris County, New Jersey, United States. As of the 2010 United States Census, the township population was 53,238, reflecting an increase of 2,589 (+5.1%) from the 50,649 counted in the 2000 Census, which had in turn increased by 2,171 (+4.5%) from the 48,478 counted in the 1990 Census.