Resident Population in Jefferson County, OK was 5.34700 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Jefferson County, OK reached a record high of 8.59600 in January of 1983 and a record low of 5.32500 in January of 2020. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Jefferson County, OK - last updated from the United States Federal Reserve on May of 2024.