Walnut Hill
- County:
- Marion County
- County Seat:
- No
- Area (mi²):
- 0.38
- State:
- Illinois
Walnut Hill is a village located in Marion County, Illinois. Walnut Hill has a 2025 population of 93 . Walnut Hill is currently declining at a rate of 0% annually and its population has decreased by -3.13% since the most recent census, which recorded a population of 96 in 2020.
The median age in Walnut Hill is 50.4 years: 44 years for males, and 58.6 years for females. For every 100 females there are 95.7 males.