Founded in 1843, Harrison County is one of 114 counties in the state of Missouri. Historically, Harrison County was formed from Daviess County. The city of Bethany is the county seat. With FIPS code of 81, Harrison County has a population of 8,164 and area of 725 square miles (1,878 km2).
List of all cities in Harrison County, MO alphabetically
| City/Town | Postal Code | Area Code |
| Bethany, MO | 64424 | 660 |
| Blythedale, MO | 64426 | 660 |
| Brimson, MO | 64642 | 660 |
| Cainsville, MO | 64632 | 660 |
| Eagleville, MO | 64442 | 660 |
| Gilman City, MO | 64642 | 660 |
| Hatfield, MO | 64458 | 660 |
| Martinsville, MO | 64467 | 660 |
| Mount Moriah, MO | 64481 | 660 |
| New Hampton, MO | 64471 | 660 |
| Ridgeway, MO | 64481 | 660 |