Erwin
- County:
- Kingsbury County
- County Seat:
- No
- Area (mi²):
- 0.476
- State:
- South Dakota
Erwin is a town located in Kingsbury County, South Dakota. Erwin has a 2026 population of 39. Erwin is currently declining at a rate of 0% annually and its population has increased by 2.63% since the most recent census, which recorded a population of 38 in 2020.
The median household income in Erwin is $86,250 with a poverty rate of 0%. The median age in Erwin is 19.9 years: 19.7 years for males, and 30.3 years for females. For every 100 females there are 144.2 males.