Marion is a city in Turner County, South Dakota, United States.

[6] Marion was laid out in 1879, and named in honor of a railroad employee's daughter.

[7] According to the United States Census Bureau, the city has a total area of 0.87 square miles (2.25 km2), all land.

There were 384 housing units at an average density of 441.4 per square mile (170.4/km2).

35.6% of all households were made up of individuals, and 24.8% had someone living alone who was 65 years of age or older.

32.3% of all households were made up of individuals, and 21.4% had someone living alone who was 65 years of age or older.