Resident Population in Morris County, NJ was 523.05300 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Morris County, NJ reached a record high of 523.05300 in January of 2024 and a record low of 383.45400 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Morris County, NJ - last updated from the United States Federal Reserve on September of 2025.