Founded in 1839, Jersey County is one of 102 counties in the state of Illinois. Historically, Jersey County was formed from Greene County. The city of Jerseyville is the county seat. With FIPS code of 83, Jersey County has a population of 21,333 and area of 369 square miles (956 km2).
List of all cities in Jersey County, IL alphabetically
| City/Town | Postal Code | Area Code |
| Chautauqua, IL | 62028 | 618/730 |
| Delhi, IL | 62052 | 618/730 |
| Dow, IL | 62022 | 618/730 |
| East Hardin, IL | 62031 | 618/730 |
| Elsah, IL | 62028 | 618/730 |
| Fidelity, IL | 62030 | 618/730 |
| Fieldon, IL | 62031 | 618/730 |
| Grafton, IL | 62037 | 618/730 |
| Jersey, IL | 62052 | 618/730 |
| Jerseyville, IL | 62052 | 618/730 |
| Kemper, IL | 62063 | 618/730 |
| McClusky, IL | 62052 | 618/730 |
| Medora, IL | 62063 | 618/730 |
| Nutwood, IL | 62031 | 618/730 |
| Otter Creek, IL | 62052 | 618/730 |
| Otterville, IL | 62037 | 618/730 |
| 62052 | 618/730 | |
| Quarry, IL | 62037 | 618/730 |
| Rosedale, IL | 62031 | 618/730 |
| Summerville, IL | 62063 | 618/730 |