Barnett is a city in Morgan County, Missouri, United States.

[5] A post office called Stone House was established in 1858, and the name was changed to Barnetsville in 1875.

[5] The Jesse Ratcliff House was listed on the National Register of Historic Places in 1982.

[8] Barnett is in eastern Morgan County on the south side of Missouri Route 52, which leads northwest 11 miles (18 km) to Versailles, the county seat, and southeast 6 miles (10 km) to Eldon.

According to the U.S. Census Bureau, Barnett has a total area of 0.27 square miles (0.70 km2), all land.

The racial makeup of the city was 93.6% White, 3.4% Native American, 0.5% Asian, and 2.5% from two or more races.

About 7.7% of families and 12.7% of the population were below the poverty line, including 22.2% of those under the age of eighteen and 17.2% of those 65 or over.