Founded in 1855, Allen County is one of 105 counties in the state of Kansas. Historically, Allen County was one of the original 36 counties. The city of Iola is the county seat. With FIPS code of 1, Allen County has a population of 12,464 and area of 503 square miles (1,303 km2).
List of all cities in Allen County, KS alphabetically
| City/Town | Postal Code | Area Code |
| Bassett, KS | 66749 | 620 |
| Carlyle, KS | 66749 | 620 |
| Elsmore, KS | 66732 | 620 |
| Gas, KS | 66742 | 620 |
| Humboldt, KS | 66748 | 620 |
| Iola, KS | 66749 | 620 |
| La Harpe, KS | 66751 | 620 |
| Moran, KS | 66755 | 620 |
| Savonburg, KS | 66772 | 620 |