Netcong is a Borough in Morris County, New Jersey, United States. As of the United States 2000 Census, the borough population was 2,580. Its estimated population in 2006 was 3,292. Netcong lies on the shores of Lake Musconetcong. Netcong was incorporated as a borough by an Act of the New Jersey Legislature on October 23, 1894, from portions of both Mount Olive Township and Roxbury Township, based on the results of a referendum held the previous day.