Harrison is an unincorporated community and census-designated place (CDP) in Douglas County, South Dakota, United States.

[5] Harrison is located in western Douglas County 6 miles (10 km) west of Corsica and 16 miles (26 km) northwest of Armour, the Douglas County seat.

According to the United States Census Bureau, the CDP has a total area of 0.11 square miles (0.28 km2), all land.

30.8% of all households were made up of individuals, and 23.1% had someone living alone who was 65 years of age or older.

There were 13.0% of families and 14.8% of the population living below the poverty line, including 36.4% of under eighteens and none of those over 64.