Waun Rydd is a mountain in the Brecon Beacons National Park, in southern Powys, Wales.

Its height is 769 m (2,523 ft) and it tops a large boggy plateau rising to the east of Pen y Fan.

It marks the top of a large landslip area extending to the stream of Blaen y Glyn below.

That known as Gist Wen runs north-northeast to the subsidiary top of Bryn (561m above sea level).

To the south a broad ridge runs to a col beyond which is the top of Allt Forgan (513m).