Hardin
- County:
- Calhoun County
- County Seat:
- Yes
- Area (mi²):
- 2.128
- State:
- Illinois
Hardin is a village located in Calhoun County, Illinois. Hardin has a 2026 population of 765. It is also the county seat of Calhoun County. Hardin is currently declining at a rate of -1.54% annually and its population has decreased by -3.65% since the most recent census, which recorded a population of 794 in 2020.