Llanarth, a parish in Monmouthshire, on an affluent of the river Usk, 3 1/4 miles E of Penpergwm station on the G.W. R., and 5 1/4 SE of Abergavenny, and has a post office under Newport; money order office, Raglan; telegraph office, Llanfihangel Gobion. It includes the hamlet of Clytha. Acreage, 3818 ; population, 563. Llanarth Court belonged to the chamberlain of Henry I., and passed to the Herberts. The living is a vicarage in the diocese of Llandaff; net value, £251 with residence. Patrons, the Dean and Chapter of Llandaff. The church is ancient, and was restored in 1891. It dates probably from the llth century, and stands on the foundation of the church which King Offa in the 7th century gave, with all its appurtenances, to the Bishop of Llandaff and his successors in the see for ever. In the churchyard there is an ancient runic cross, which was restored in 1886. There is a Roman Catholic chapel.