Resident Population in Lamar County, GA was 20.69000 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Lamar County, GA reached a record high of 20.69000 in January of 2024 and a record low of 10.68800 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Lamar County, GA - last updated from the United States Federal Reserve on April of 2026.