Gerster is a town in St. Clair County, Missouri, United States.

[5] A post office called Gerster was established in 1898, and remained in operation until 1958.

[6] According to the United States Census Bureau, the village has a total area of 0.08 square miles (0.21 km2), all land.

46.2% of all households were made up of individuals, and 15.4% had someone living alone who was 65 years of age or older.

20.0% of all households were made up of individuals, and none had someone living alone who was 65 years of age or older.

There were 60.0% of families and 74.3% of the population living below the poverty line, including 100.0% of under eighteens and none of those over 64.