Castlewood township
- County:
- Hamlin County
- County Seat:
- No
- Area (mi²):
- 34.576
- State:
- South Dakota
Castlewood township is located in Hamlin County, South Dakota. Castlewood township has a 2026 population of 259. Castlewood township is currently growing at a rate of 2.37% annually and its population has increased by 8.82% since the most recent census, which recorded a population of 238 in 2020.
The median household income in Castlewood township is $156,667 with a poverty rate of 2.14%. The median age in Castlewood township is 32.4 years: 38.1 years for males, and 26.3 years for females. For every 100 females there are 141.3 males.