St Llwchaiarn's Church is situated within an irregularly-shaped churchyard. An eighth-ninth century cross-incised stone (NPRN 301818) is known to have been present within the church since at least the 1930s. A church or chapel is known to have been sited here during the post-conquest period. It is thought to have been a possession of the Bishops of St Davids from an early date. The church's medieval font bowl is square and lies loose in the church. It has four human masks (carved in relief) at each corner and is similar to that at St Sulien's Church, Silian (NPRN 402554), St Patrick's Church, Pencarreg (NPRN 418382), St Llawddog's Church, Cenarth (NPRN 309895) (taken from St Tysilio's Church, Llandisiliogogo, NPRN 400361) and St Mary's Church, Llanfair Clydogau (NPRN 402887). In 1833 it was noted that there had formerly been a medieval cross-base in the churchyard. The church formerly had an Elizabethan chalice. By 1833 the church was a parish church in the patronage of the Bishop of St Davids.

The earlier church was described as ancient in 1833. It comprised nave and chancel with two-centred chancel arch. The church was demolished in 1863.

It was rebuilt in 1865, to the designs of R.J. Withers, London. The present church, a Grade II listed building, is constructed of snecked rubble-stone with Bathstone dressings. It consists of two-bayed chancel, four-bayed nave, west porch/bell turret, organ chamber/ boilerhouse (south of nave east bay) and vestry (south of chancel west bay). The current font dates from the nineteenth century. The vestry, by W.D. Caroe, was added in 1935 and the chancel furnishings also date to this time. The organ dates from around 1990.

Sources include:
Cadw, Listed Buildings Database
Cambria Archaeology, 2000, Ceredigion Churches, gazetteer, 48
Edwards, N. 2007, A Corpus of Early Medieval Inscribed Stones and Stone Sculpture in Wales: Volume II South-West Wales

N Vousden, RCAHMW, 12 May 2014