Founded in 1827, Jo Daviess County is one of 102 counties in the state of Illinois. Historically, Jo Daviess County was formed from Henry, Mercer, and Putnam County. The city of Galena is the county seat. With FIPS code of 85, Jo Daviess County has a population of 21,939 and area of 600 square miles (1,554 km2).
List of all cities in Jo Daviess County, IL alphabetically
| City/Town | Postal Code | Area Code |
| Apple River, IL | 61001 | 815/779 |
| East Dubuque, IL | 61025 | 815/779 |
| Elizabeth, IL | 61028 | 815/779 |
| Galena, IL | 61036 | 815/779 |
| Hanover, IL | 61041 | 815/779 |
| Menominee, IL | 61025 | 815/779 |
| Nora, IL | 61059 | 815/779 |
| Scales Mound, IL | 61075 | 815/779 |
| Stockton, IL | 61085 | 815/779 |
| Warren, IL | 61087 | 815/779 |
| Woodbine, IL | 61028 | 815/779 |
| 61085 | 815/779 |