Resident Population in Sussex County, NJ was 146.13200 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Sussex County, NJ reached a record high of 151.68200 in January of 2007 and a record low of 77.52800 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Sussex County, NJ - last updated from the United States Federal Reserve on May of 2024.