Resident Population in Jefferson County, AR was 63.67200 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Jefferson County, AR reached a record high of 90.71800 in January of 1980 and a record low of 63.53900 in January of 2023. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Jefferson County, AR - last updated from the United States Federal Reserve on April of 2026.