7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Oquawka | 1 | 1,046 | 1,129 | -1.32% | 712 | 1 | Village |
| Stronghurst | 2 | 752 | 812 | -1.31% | 861 | 1 | Village |
| Lomax | 3 | 367 | 403 | -1.61% | 309 | 1 | Village |
| Biggsville | 4 | 280 | 301 | -1.06% | 831 | 0 | Village |
| Gladstone | 5 | 215 | 232 | -1.38% | 597 | 0 | Village |
| Media | 6 | 108 | 117 | -0.92% | 64 | 2 | Village |
| Raritan | 7 | 95 | 103 | -1.04% | 1,000 | 0 | Village |
Oquawka is the largest city in Henderson County, with a population of 1,046.
Raritan is the smallest city in Henderson County, with a population of 95.
There are 7 cities in Henderson County, Illinois.