Llanymawddwy is a village in Gwynedd, Wales, which is to the north of the larger village of Dinas Mawddwy, on the minor road which connects Dinas Mawddwy to Llanuwchllyn over Bwlch y Groes. The most notable building is St. Tydecho parish church, where the tradition of singing Matins endures.
Alfred George Edwards, the first Archbishop of the disestablished Church in Wales, was born in Llanymawddwy in 1848.
According to local tradition, Bryn Hall was once haunted by a headless horseman. The haunting is said to have ceased after a grave belonging to the Lord's illegitimate child was found near the hall.