| Official Name: | Rhos-y-gwaliau |
| Country: | Wales |
| Static Image Name: | Capel Rhos-y-gwaliau - geograph.org.uk - 406356.jpg |
| Static Image Caption: | Village chapel |
| Population: | 86 |
| Population Ref: | (2011) |
| Os Grid Reference: | SH9434 |
| Coordinates: | 52.9001°N -3.5732°W |
| Post Town: | BALA |
| Postcode Area: | LL |
| Postcode District: | LL23 |
| Dial Code: | 01678 |
| Constituency Westminster: | Dwyfor Meirionnydd |
| Cardiff Distance: | 140 miles |
| Community Wales: | Llandderfel |
| Unitary Wales: | Gwynedd |
Rhos-y-gwaliau is a small hamlet in Meirionnydd, Gwynedd, North Wales, about 1.5miles south-east of Bala. It is home to the Rhos y Gwaliau Outdoor Activity Centre and a now disused Victorian chapel, built for the Calvinistic Methodists.
The Berwyn Mountains rise behind the village. The village lies towards the lower end of the narrow Hirnant valley formed by the Hirnant stream, which rises at the crest of the Berwyns and flows into the River Dee. The valley gives its name to the Hirnantian Age in the Ordovician Period of geological time.
Close to the village is Plas Rhiwaedog, the manor house of the ancient Rhiwaedog estate.
Regional Cycle Route 12 passes through the village.