St. Paul is a city in St. Charles County, Missouri, United States.

A post office called Saint Paul was established in 1875, and remained in operation until 1964.

[5] According to the United States Census Bureau, the city has a total area of 6.68 square miles (17.30 km2), all land.

There were 656 housing units at an average density of 98.2 per square mile (37.9/km2).

10.8% of all households were made up of individuals, and 5% had someone living alone who was 65 years of age or older.

8.9% of all households were made up of individuals, and 4.9% had someone living alone who was 65 years of age or older.