Route 181 is a 7.47-mile (12.02 km) state highway in Jefferson Township and Sparta Township in New Jersey. The highway begins in Jefferson Township at a cloverleaf interchange with Route 15 and Espanong Road. Route 181 serves as the local route through Woodport, serving the eastern shores of Lake Hopatcong as well as the main road through the center of Sparta. The route terminates at a jughandle with Route 15 in Sparta.

Jefferson Township is the northernmost township in Morris County, in the U.S. state of New Jersey. As of the 2020 United States census, the township's population was 20,538, a decrease of 776 (−3.6%) from the 2010 census count of 21,314, which in turn reflected an increase of 1,597 (+8.1%) from the 19,717 counted in the 2000 census.