Mount Olive Township is a township in western Morris County, in the U.S. state of New Jersey. As of the 2020 United States census, the township's population was 28,886,
The Township of Mount Olive was formed by an act of the New Jersey Legislature on March 22, 1871, from portions of Roxbury Township. Netcong was formed from portions of the township on October 23, 1894.
The township comprises the unincorporated communities of Budd Lake and Flanders. Located within the Raritan Valley region, Mount Olive is situated in western Morris County bordering both Sussex and Warren counties along the Musconetcong River.
Geography
According to the United States Census Bureau, the township had a total area of 31.24 square miles (80.92 km<sup>2</sup>), including 29.62 square miles (76.71 km<sup>2</sup>) of land and 1.63 square miles (4.21 km<sup>2</sup>) of water (5.21%).
Other unincorporated communities, localities and place names located partially or completely within the township include Bartley, Saxton Falls and Waterloo.
The township borders the municipalities of Chester Township, Netcong, Roxbury, and Washington Township in Morris County; Stanhope in Sussex County; and Allamuchy and Hackettstown in Warren County.