St. Anthony is a city in Marshall County, Iowa, United States.

[5] According to the United States Census Bureau, the city has a total area of 0.56 square miles (1.45 km2), all land.

There were 42 housing units at an average density of 68.5 per square mile (26.5/km2).

There were 50 housing units at an average density of 89.3 per square mile (34.5/km2).

25.0% of all households were made up of individuals, and 5% had someone living alone who was 65 years of age or older.

There were 52 housing units at an average density of 92.8 per square mile (35.8/km2).

25.0% of all households were made up of individuals, and 6.8% had someone living alone who was 65 years of age or older.

There were 7.9% of families and 13.1% of the population living below the poverty line, including 15.4% of under eighteens and 5.3% of those over 64.