Founded on Jan 21, 1839, Jefferson County is one of 99 counties in the state of Iowa. Historically, Jefferson County was formed from Native American lands. The city of Fairfield is the county seat. With FIPS code of 101, Jefferson County has a population of 15,647 and area of 435 square miles (1,127 km2).
List of all cities in Jefferson County, IA alphabetically
| City/Town | Postal Code | Area Code |
| Abingdon, IA | 52533 | 641 |
| Batavia, IA | 52533 | 641 |
| Beckwith, IA | 52556 | 641 |
| Fairfield, IA | 52556 | 641 |
| 52557 | 641 | |
| Four Corners, IA | 52635 | 319 |
| Glasgow, IA | 52556 | 641 |
| Libertyville, IA | 52567 | 641 |
| Limby, IA | 52580 | 319 |
| Lockridge, IA | 52635 | 319 |
| Maharishi University of Mgmt, IA | 52557 | 641 |
| Packwood, IA | 52580 | 319 |
| Pekin, IA | 52580 | 319 |
| Perlee, IA | 52556 | 641 |
| Salina, IA | 52556 | 641 |
| Vedic City, IA | 52556 | 641 |