St. Lucas
- County:
- Fayette County
- County Seat:
- No
- Area (mi²):
- 0.254
- State:
- Iowa
St. Lucas is a city located in Fayette County, Iowa. St. Lucas has a 2026 population of 167. St. Lucas is currently declining at a rate of 0% annually and its population has decreased by 0% since the most recent census, which recorded a population of 167 in 2020.
The median household income in St. Lucas is $104,375 with a poverty rate of 5.84%. The median age in St. Lucas is 37.5 years: 40 years for males, and 35.5 years for females. For every 100 females there are 113.9 males.