| State: | KY |
| Type: | KY |
| Route: | 78 |
| Map Custom: | yes |
| Map Notes: | KY 78 highlighted in red |
| Length Mi: | 25.300 |
| Length Ref: | [1] |
| Direction A: | West |
| Terminus A: | in rural Casey Co |
| Junction: | in Hustonville in Stanford |
| Direction B: | East |
| Terminus B: | near Stanford |
| Counties: | Casey, Lincoln |
| Previous Type: | KY |
| Previous Route: | 77 |
| Next Type: | US |
| Next Route: | 79 |
Kentucky Route 78 (KY 78) is a 25.3-longNaN-long state highway in Kentucky that runs from KY 49 in rural Casey County northwest of Liberty to U.S. Route 150 (US 150) southeast of Stanford via Hustonville and Stanford. Much of the route follows the old Cumberland Trail from Stanford, KY to Nashville, TN.