Founded in Mar 1, 1810, Guernsey County is one of 88 counties in the state of Ohio. Historically, Guernsey County was formed from Belmont and Muskingum Counties. The city of Cambridge is the county seat. With FIPS code of 59, Guernsey County has a population of 38,287 and area of 521.90 square miles (1,352 km2).
List of all cities in Guernsey County, OH alphabetically
| City/Town | Postal Code | Area Code |
| Buffalo, OH | 43722 | 740 |
| Byesville, OH | 43723 | 740 |
| Cambridge, OH | 43725 | 740 |
| 43750 | 740 | |
| Claysville, OH | 43725 | 740 |
| Cumberland, OH | 43732 | 740 |
| Derwent, OH | 43733 | 740 |
| Fairview, OH | 43736 | 740 |
| Guernsey, OH | 43749 | 740 |
| Kimbolton, OH | 43749 | 740 |
| Kipling, OH | 43750 | 740 |
| Lore City, OH | 43755 | 740 |
| Old Washington, OH | 43768 | 740 |
| Pleasant City, OH | 43772 | 740 |
| Quaker City, OH | 43736 | 740 |
| 43773 | 740 | |
| Salesville, OH | 43778 | 740 |
| Senecaville, OH | 43780 | 740 |