Resident Population in Marion County, TN was 29.38200 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Marion County, TN reached a record high of 29.38200 in January of 2023 and a record low of 20.57700 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Marion County, TN - last updated from the United States Federal Reserve on May of 2024.