Mill Spring is a village in Wayne County, Missouri, United States, along the Black River.

[7] Millspring post office was shut down in 2014 Mill Spring is located in a tributary valley on the northeast edge of the Black River floodplain.

The community of Leeper is approximately one mile to the northwest along Missouri Route 49.

[8] According to the United States Census Bureau, the village has a total area of 0.44 square miles (1.14 km2), all land.

The racial makeup was 96.35% White, 0.46% Native American, 0.91% Pacific Islander and 2.28% from two or more races.

About 13.5% of families and 22.7% of the population were below the poverty line, including 25.0% of those under the age of eighteen and 20.0% of those 65 or over.