| State: | MO |
| Type: | Route |
| Route: | 139 |
| Map Custom: | yes |
| Map Notes: | MO 139 highlighted in red |
| Length Mi: | 108.565 |
| Direction A: | South |
| Terminus A: | east of Carrollton |
| Junction: | |
| Direction B: | North |
| Terminus B: | at the Iowa state line |
| Previous Type: | MO |
| Previous Route: | 138 |
| Next Type: | MO |
| Next Route: | 141 |
Route 139 is a highway in northern and central Missouri. Its northern terminus is at the Iowa state line where it continues as Wayne County Route S40; its southern terminus is at U.S. Route 24 east of Carrollton.