Allison
- County:
- Brown County
- County Seat:
- No
- Area (mi²):
- 35.888
- State:
- South Dakota
Allison is located in Brown County, South Dakota. Allison has a 2025 population of 27 . Allison is currently declining at a rate of 0% annually and its population has increased by 3.85% since the most recent census, which recorded a population of 26 in 2020.
The median age in Allison is 15.3 years: 13 years for males, and 17.3 years for females. For every 100 females there are 160.0 males.