Founded in 1873, Thomas County is one of 105 counties in the state of Kansas. Historically, Thomas County was formed from unorganized area. The city of Colby is the county seat. With FIPS code of 193, Thomas County has a population of 7,877 and area of 1,075 square miles (2,784 km2).
List of all cities in Thomas County, KS alphabetically
| City/Town | Postal Code | Area Code |
| Brewster, KS | 67732 | 785 |
| Colby, KS | 67701 | 785 |
| Gem, KS | 67734 | 785 |
| Levant, KS | 67743 | 785 |
| Menlo, KS | 67753 | 785 |
| Rexford, KS | 67753 | 785 |