Founded in 1855, Leavenworth County is one of 105 counties in the state of Kansas. Historically, Leavenworth County was one of the original 36 counties. The city of Leavenworth is the county seat. With FIPS code of 103, Leavenworth County has a population of 82,184 and area of 463 square miles (1,199 km2).
List of all cities in Leavenworth County, KS alphabetically
| City/Town | Postal Code | Area Code |
| Basehor, KS | 66007 | 913 |
| Easton, KS | 66020 | 913 |
| Fort Leavenworth, KS | 66027 | 913 |
| Lansing, KS | 66043 | 913 |
| Leavenworth, KS | 66043 | 913 |
| 66048 | 913 | |
| Linwood, KS | 66052 | 913 |
| Tonganoxie, KS | 66086 | 913 |