| Martins Fork | |
| Mouth Location: | Harlan, Kentucky |
| Progression: | Cumberland—Ohio—Mississippi |
| Length: | 32miles |
| Mouth Elevation: | 1158feet |
| Mouth Coordinates: | 36.845°N -83.3242°W |
| Discharge1 Location: | Harlan, Kentucky |
| Discharge1 Avg: | 243 cu/ft. per sec.[1] |
Martins Fork is a 32miles[2] river in Bell and Harlan Counties in Kentucky in the United States. The river flows east and north from its source in the Cumberland Mountains, a subrange of the Appalachian Mountains, to its confluence with the Poor Fork at Baxter. The confluence marks the official beginning of the Cumberland River.