McDonald County is a county located in the southwestern corner of the U.S. state of Missouri. As of the 2020 census, the population was 23,303. and was estimated to be 23,992 in 2025.
History
The county was organized in 1849 and named for Sergeant Alexander McDonald, a soldier in the American Revolutionary War. The county has three sites on the National Register of Historic Places, including the Old McDonald County Courthouse and the Powell Bridge.
Geography
According to the United States Census Bureau, the county has a total area of , of which is land and (0.04%) is water. It is the 71st largest county in Missouri by total area.
Adjacent counties
- Newton County (north)
- Barry County (east)
- Benton County, Arkansas (south)
- Delaware County, Oklahoma (west)
- Ottawa County, Oklahoma (northwest)