Resident Population in Clay County, MS was 18.20600 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Clay County, MS reached a record high of 21.98500 in January of 2000 and a record low of 18.20600 in January of 2023. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Clay County, MS - last updated from the United States Federal Reserve on May of 2024.