Founded on Jan 15, 1851, Osceola County is one of 99 counties in the state of Iowa. Historically, Osceola County was formed from Woodbury County. The city of Sibley is the county seat. With FIPS code of 143, Osceola County has a population of 6,159 and area of 399 square miles (1,033 km2).
List of all cities in Osceola County, IA alphabetically
| City/Town | Postal Code | Area Code |
| Allendorf, IA | 51354 | 712 |
| Ashton, IA | 51232 | 712 |
| Cloverdale, IA | 51249 | 712 |
| Harris, IA | 51345 | 712 |
| May City, IA | 51354 | 712 |
| Melvin, IA | 51350 | 712 |
| Ocheyedan, IA | 51354 | 712 |
| Sibley, IA | 51249 | 712 |