Llanrhaeadr-ym-Mochnant is a village and community located in Powys, Wales. It is situated on the B4580 road, approximately 9 miles west of Oswestry and 12 miles south of Llangollen. The settlement lies near the foothills of the Berwyn mountains along the river Rhaeadr.
The area is notable for its proximity to the Pistyll Rhaeadr waterfall, located at the top end of the valley, which is recognized as one of the traditional Seven Wonders of Wales. Other local landmarks include the hill Moel Hen-fache, situated one mile north of the village. The community also encompasses the hamlet of Llanarmon Mynydd Mawr.