| Name | Location | County | Country | Power source | Type | Function | River |
| Gwynllyn Mill, Rhayader | Rhayader | Radnorshire | United Kingdom | Water | Watermill | Corn mill | Nant Gwynllyn |
| Lower Mill, Rhayader | Rhayader | Radnorshire | United Kingdom | Water | Watermill | Corn mill | Nant Gwynllyn |
| Saw mill, Dderw Estate, Rhayader | Rhayader | Radnorshire | United Kingdom | Water | Watermill | Saw mill | Nant Gwynllyn |
| Tannery, Rhayader | Rhayader | Radnorshire | United Kingdom | Water | Watermill | Bark mill, Tannery | Wye |