| Duncan, SC (Town) |
| Duncan, MO (Township) |
| Duncan, MS (Town) |
| Duncan, OK (City) |
| Duncan, AZ (Town) |
| Duncan Township, IL (Township) |
| Duncan Township, PA (Township) |
| Duncan Township, MI (Township) |
| Duncannon, PA (Borough) |
| Duncansville, PA (Borough) |
| Duncanville, TX (City) |
| Duncombe, IA (City) |
| Dundas, MN (City) |
| Dundee, MN (City) |
| Dundee, IA (City) |
