Grassland Colony
- County:
- Brown County
- County Seat:
- No
- Area (mi²):
- 0.426
- State:
- South Dakota
Grassland Colony is a CDP located in Brown County, South Dakota. Grassland Colony has a 2025 population of 22. Grassland Colony is currently growing at a rate of 4.76% annually and its population has decreased by 0% since the most recent census, which recorded a population of 0 in 2020.
The median age in Grassland Colony is 45 years: 45.1 years for males, and 0 years for females.