Founded on Jan 13, 1846, Jasper County is one of 99 counties in the state of Iowa. Historically, Jasper County was formed from Mahaska County. The city of Newton is the county seat. With FIPS code of 99, Jasper County has a population of 37,764 and area of 730 square miles (1,891 km2).
List of all cities in Jasper County, IA alphabetically
| City/Town | Postal Code | Area Code |
| Amboy, IA | 50208 | 641 |
| Baxter, IA | 50028 | 641 |
| Colfax, IA | 50054 | 515 |
| Galesburg, IA | 50232 | 641 |
| Goddard, IA | 50054 | 515 |
| Green Castle, IA | 50054 | 515 |
| Ira, IA | 50127 | 641 |
| Kellogg, IA | 50135 | 641 |
| Killduff, IA | 50137 | 641 |
| Lambs Grove, IA | 50208 | 641 |
| Lynnville, IA | 50153 | 641 |
| Mingo, IA | 50168 | 641 |
| Monroe, IA | 50170 | 641 |
| Newton, IA | 50208 | 641 |
| Prairie City, IA | 50228 | 515 |
| Reasnor, IA | 50232 | 641 |
| Sully, IA | 50251 | 641 |
| Valeria, IA | 50054 | 515 |