| Official Name: | Duncan, Kentucky |
| Settlement Type: | Unincorporated community |
| Pushpin Map: | Kentucky |
| Pushpin Label: | Duncan |
| Pushpin Label Position: | left |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Kentucky |
| Subdivision Type2: | County |
| Subdivision Name2: | Mercer |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation Ft: | 837 |
| Coordinates: | 37.8492°N -84.9903°W |
| Area Code: | 859 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 491290 |
Duncan is an unincorporated community in Mercer County, Kentucky, United States. Duncan is located at the junction of Kentucky Route 390 and Kentucky Route 1941, 10miles northwest of Harrodsburg.[1]
A post office was established in the community in 1842, and it was probably named for prominent citizen John Ray Duncan.[2]