Founded on Jan 15, 1851, Lyon County is one of 99 counties in the state of Iowa. Historically, Lyon County was formed from Woodbury County, Iowa. The city of Rock Rapids is the county seat. With FIPS code of 119, Lyon County has a population of 12,011 and area of 588 square miles (1,523 km2).
List of all cities in Lyon County, IA alphabetically
| City/Town | Postal Code | Area Code |
| Alvord, IA | 51230 | 712 |
| Doon, IA | 51235 | 712 |
| Edna, IA | 51246 | 712 |
| George, IA | 51237 | 712 |
| Granite, IA | 51241 | 712 |
| Inwood, IA | 51240 | 712 |
| Larchwood, IA | 51241 | 712 |
| Lester, IA | 51242 | 712 |
| Little Rock, IA | 51243 | 712 |
| Rock Rapids, IA | 51246 | 712 |