| State: | KY |
| Type: | KY |
| Route: | 81 |
| Map Custom: | yes |
| Map Notes: | KY 81 highlighted in red |
| Length Mi: | 39.961 |
| Length Ref: | [1] |
| Direction A: | South |
| Terminus A: | in South Carrollton |
| Junction: | near Owensboro |
| Direction B: | North |
| Terminus B: | in Owensboro |
| Counties: | Muhlenberg, McLean, Daviess |
| Previous Type: | KY |
| Previous Route: | 80 |
| Next Type: | KY |
| Next Route: | 82 |
Kentucky Route 81 is a 39.961-mile (64.331 km) state highway in Kentucky that runs from U.S. Route 431 in South Carrollton to Kentucky Route 2831 and Kentucky Route 81 in Owensboro via Bremen, Sacramento, Rumsey, and Calhoun.