Millersburg
- County:
- Mercer County
- County Seat:
- No
- Area (mi²):
- 0.297
- State:
- Illinois
Millersburg is a CDP located in Mercer County, Illinois. Millersburg has a 2025 population of 78 . Millersburg is currently growing at a rate of 8.33% annually and its population has increased by 2.63% since the most recent census, which recorded a population of 76 in 2020.
The median age in Millersburg is 64.1 years: 0 years for males, and 62.4 years for females. For every 100 females there are 44.0 males.