Castalia
- County:
- Winneshiek County
- County Seat:
- No
- Area (mi²):
- 0.578
- State:
- Iowa
Castalia is a city located in Winneshiek County, Iowa. Castalia has a 2026 population of 141. Castalia is currently declining at a rate of -0.7% annually and its population has decreased by -3.42% since the most recent census, which recorded a population of 146 in 2020.
The median household income in Castalia is $61,250 with a poverty rate of 7.86%. The median age in Castalia is 58 years: 59.2 years for males, and 57.8 years for females. For every 100 females there are 94.5 males.