Resident Population in Marion County, KY was 19.83400 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Marion County, KY reached a record high of 20.01200 in January of 2011 and a record low of 16.51000 in January of 1990. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Marion County, KY - last updated from the United States Federal Reserve on May of 2024.