St. Thomas is a city in Cole County, Missouri, United States.

[5] It is part of the Jefferson City, Missouri Metropolitan Statistical Area.

[8] According to the United States Census Bureau, the city has a total area of 0.98 square miles (2.54 km2), all land.

There were 100 housing units at an average density of 102.0 per square mile (39.4/km2).

The racial makup of the city was 99.2% White, 0.4% African American, and 0.4% from two or more races.

About 5.9% of families and 6.2% of the population were below the poverty line, including 9.0% of those under the age of eighteen and 11.3% of those sixty five or over.