| Waun-oer | |
| Elevation M: | 670 |
| Prominence M: | 119 |
| Range: | Cadair Idris |
| Listing: | Hewitt, Nuttall, HuMP |
| Translation: | Cold Bog |
| Language: | Welsh |
| Location: | Snowdonia, Wales |
| Coordinates: | 52.7171°N -3.7985°W |
| Map: | Wales |
| Grid Ref Uk: | SH785147 |
| Topo: | OS Explorer OL23 |
| Fetchwikidata: | ALL |
Waun-oer is a mountain in Snowdonia, North Wales, situated approximately four miles to the south-west of Aran Fawddwy. It is one of the peaks in the Dyfi hills, a subgroup of the Cadair Idris group. It is a top of Maesglase and the summit consists of a trig point that crowns an uneven grassy plateau. It is connected to Cribin Fawr to the east and Mynydd Ceiswyn to the south. To the north lies Cadair Idris, while Tarren y Gesail lies to the west.[1]