| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Rosiclare | 1 | 973 | 999 | -0.41% | 502 | 2 | City |
| Elizabethtown | 2 | 223 | 230 | -0.89% | 316 | 1 | Village |
| Cave-In-Rock | 3 | 220 | 228 | -0.9% | 588 | 0 | Village |
Rosiclare is the largest city in Hardin County, with a population of 973.
Cave-In-Rock is the smallest city in Hardin County, with a population of 220.
There are 3 cities in Hardin County, Illinois.