
Allen
- County:
- Bennett County
- County Seat:
- No
- Area (mi²):
- 3.244
- State:
- South Dakota
Allen is a CDP located in Bennett County, South Dakota. Allen has a 2025 population of 1,052. Allen is currently growing at a rate of 4.16% annually and its population has increased by 120.55% since the most recent census, which recorded a population of 477 in 2020.
The average household income in Allen is $45,009 with a poverty rate of 34.42%. The median age in Allen is 20.2 years: 13.8 years for males, and 20.3 years for females.