Resident Population in McDonald County, MO was 24.05400 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in McDonald County, MO reached a record high of 24.11700 in January of 2023 and a record low of 12.35700 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in McDonald County, MO - last updated from the United States Federal Reserve on April of 2026.