Plainville
- County:
- Adams County
- County Seat:
- No
- Area (mi²):
- 0.235
- State:
- Illinois
Plainville is a village located in Adams County, Illinois. Plainville has a 2026 population of 260. Plainville is currently declining at a rate of -0.38% annually and its population has decreased by -3.7% since the most recent census, which recorded a population of 270 in 2020.
The median household income in Plainville is $76,250 with a poverty rate of 8.74%. The median age in Plainville is 49.9 years: 53.5 years for males, and 47.8 years for females. For every 100 females there are 125.9 males.