Resident Population in Jefferson County, AL was 664.74400 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Jefferson County, AL reached a record high of 674.72700 in January of 2020 and a record low of 644.99100 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Jefferson County, AL - last updated from the United States Federal Reserve on April of 2026.