Llantilio Pertholey (Welsh: Llandeilo Bertholau) is a small village in Monmouthshire, south east Wales. It is located 1.5 miles (2.4 km) to the north-east of the market town of Abergavenny, just off the A465 road to Hereford. The parish covers a large area beneath the Skirrid, an outlier of the Black Mountains; much of the parish lies within the easternmost part of the Brecon Beacons National Park.