Founded in 1825, Henry County is one of 102 counties in the state of Illinois. Historically, Henry County was formed from Fulton County. The city of Cambridge is the county seat. With FIPS code of 73, Henry County has a population of 48,907 and area of 822 square miles (2,129 km2).
List of all cities in Henry County, IL alphabetically
| City/Town | Postal Code | Area Code |
| Alba, IL | 61235 | 309 |
| Alpha, IL | 61413 | 309 |
| Andover, IL | 61233 | 309 |
| Annawan, IL | 61234 | 309 |
| 61258 | 815/779 | |
| Atkinson, IL | 61235 | 309 |
| Bishop Hill, IL | 61419 | 309 |
| Cambridge, IL | 61238 | 309 |
| Cleveland, IL | 61241 | 309 |
| Colona, IL | 61241 | 309 |
| Cornwall, IL | 61235 | 309 |
| Galva, IL | 61434 | 309 |
| Geneseo, IL | 61254 | 309 |
| Green Rock, IL | 61241 | 309 |
| Hanna, IL | 61254 | 309 |
| Hooppole, IL | 61258 | 815/779 |
| Kewanee, IL | 61443 | 309 |
| Lynn, IL | 61262 | 309 |
| Lynn Center, IL | 61262 | 309 |
| Munson, IL | 61238 | 309 |
| Nekoma, IL | 61490 | 309 |
| Opheim, IL | 61468 | 309 |
| 61468 | 309 | |
| Orion, IL | 61273 | 309 |
| Osco, IL | 61274 | 309 |
| Sunny Hill, IL | 61273 | 309 |
| Sunny Hill Estates, IL | 61273 | 309 |
| Swedona, IL | 61262 | 309 |
| Ulah, IL | 61238 | 309 |
| Warner, IL | 61273 | 309 |
| Weller, IL | 61238 | 309 |
| Western, IL | 61273 | 309 |
| Woodhull, IL | 61490 | 309 |