St Mary's Church is situated within a curvilinear churchyard, bounded by roads to the north-east. To the immediate east of the churchyard (seperated by the road) is the farm of Llanfair-fawr. Aerial reconnaissance in 2002 identified traces of a curving outer bank to the east of the church (at SN 625 512) which may be vestigial remains of concentric outer enclosure, potentially showing the boundary of an early church site. During the medieval period the church was a chapelry belonging to the Deanery of Sub-Aeron. By 1833 the church was a parish church. Its living, consolidated with that of Llangybi, was a perpatual curacy of the Archdeaconry of Cardigan, in the alternate patronage of the Earl of Lisburne and Lord Carrington.

The church is constructed of local rubble stone with yellow oolite dressings. It consists of five-bayed nave and chancel, west porch north vestry (north of the chancel west bay) and western double bellcote. Floors are suspended over an underfloor void. The lower half of the nave and chancel walls are thought to be thirteenth or fourteenth century in date. The circular font bowl, thought to date to around 1200, has representations of the four evangelists. In 1783 the church roof was still thatched and a timber rood screen was present. The church is thought to have been restored in 1829, and by 1844 had a west porch and another structure (possibly a vestry) abutting the north wall. The church was agin restored in the years preceding 1861. All earlier features are thought to have been removed by or at this time. The final nineteenth-century restoration was undertaken in 1886-1888, to the designs of Middleton, Prothero and Philpott of Westminster, Cheltenham and Newport. The upper half of the nave and chancel walls were rebuilt, the west porch was rebuilt and the vestry was added. The church was also refenestrated, reroofed, refloored, reseated and internally replastered. The alter rail, vestry screen and pulpit also date from this time.

Sources include:
Cambria Archaeology, 2000, Ceredigion Churches, gazetteer, 48

N Vousden, RCAHMW, 9 July 2014