Hamburg is a borough in Sussex County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 3,266, a decrease of 11 (−0.3%) from the 2010 census count of 3,277, which in turn reflected an increase of 172 (+5.5%) from the 3,105 counted in the 2000 census. The United States Census Bureau's Population Estimates Program calculated that the population of Hamburg increased by 42 (+1.3%) to 3,308 in 2022.

Hardyston Township is a township in Sussex County, in the U.S. state of New Jersey. As of the 2020 United States census, the township's population was 8,125, a decrease of 88 (−1.1%) from the 2010 census count of 8,213, which in turn reflected an increase of 2,042 (+33.1%) from the 6,171 counted in the 2000 census.