Llantilio Pertholey (Welsh: Llandeilo Bertholau) is a small village in Monmouthshire, south east Wales, in the United Kingdom.
A small hamlet to the north of the Mardy sited a mile to the north of the market town of Abergavenny just off the A465 Abergavenny to Hereford road. It is also the name of the Parish Council
Llantilio is thought to be derived from the church of st teilo ( llan = church of)
The hamlet has a primary school which moved to the Mardy in 1991 and a 13th century medieval church, named for Saint Teilo, a 6th century Bishop of Llandaff canonised into a saint for his good works. The church is a fine example of a rural Welsh church with three chantry chapels dating from maybe 1350.
The hamlet is situated beneath the Holy Mountain, the big Skirrid, an outlier of the Black Mountains, Wales and the easternmost part of the Brecon Beacons National Park.
The popular pub The Mitre conveniently opposite the church closed some years ago