Parsippany–Troy Hills, commonly known as Parsippany, is a township in Morris County, in the northern portion of the U.S. state of New Jersey. As of the 2020 United States census, the township's population was 56,162, an increase of 2,924 from the 2010 census count of 53,238, which in turn had reflected an increase of 2,589 from the 50,649 counted at the 20…Parsippany–Troy Hills, commonly known as Parsippany, is a township in Morris County, in the northern portion of the U.S. state of New Jersey. As of the 2020 United States census, the township's population was 56,162, an increase of 2,924 from the 2010 census count of 53,238, which in turn had reflected an increase of 2,589 from the 50,649 counted at the 2000 census.