Kosciusko township
- County:
- Day County
- County Seat:
- No
- Area (mi²):
- 39.605
- State:
- South Dakota
Kosciusko township is located in Day County, South Dakota. Kosciusko township has a 2026 population of 182. Kosciusko township is currently declining at a rate of -0.55% annually but its population has increased by 1.68% since the most recent census, which recorded a population of 179 in 2020.
The median household income in Kosciusko township is $105,139 with a poverty rate of 3.93%. The median age in Kosciusko township is 63.6 years: 63.1 years for males, and 65.8 years for females. For every 100 females there are 114.0 males.