Llanddew is a small village and community about 2 km or 1 mile north-east of Brecon, Powys, Wales. The population as of the 2011 UK Census was 232. It is in the historic county of Brecknockshire. Its manor belongs to the Bishops of Saint Davids, who formerly had a residence or bishop's palace there, of which some ruins still remain. These incorporate a double-sided vaulted well, known as Bishop Gower's Well.