Resident Population in Spencer County, KY was 20.53100 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Spencer County, KY reached a record high of 20.53100 in January of 2023 and a record low of 5.48800 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Spencer County, KY - last updated from the United States Federal Reserve on May of 2024.