High Quality Content by WIKIPEDIA articles! Mount Olive Township is a Township in Morris County, New Jersey, United States. As of the 2010 United States Census, the township`s population was 28,117, reflecting an increase of 3,924 (+16.2%) from the 24,193 counted in the 2000 Census, which had in turn increased by 2,911 (+13.7%) from the 21,282 counted in the 1990 Census.