Farmington
- County:
- Day County
- County Seat:
- No
- Area (mi²):
- 35.494
- State:
- South Dakota
Farmington is located in Day County, South Dakota. Farmington has a 2025 population of 27 . Farmington is currently declining at a rate of -3.57% annually and its population has decreased by 0% since the most recent census, which recorded a population of 27 in 2020.
The median age in Farmington is 74.2 years: 0 years for males, and 0 years for females. For every 100 females there are 325.0 males.