St Mary's Church was a chapelry to St Peters until 1843, after which it became an independent parish. In 1710 the building was noted to be disused and roofless. It was rebuilt around 1711, at the instigation of John Vaughan of Derllys Court (died 1722). The church is situated within a rectilinear churchyard, which has a lych gate in its north-east boundary.

The church is a Grade II* listed building, constructed of limestone rubble. It consists of chancel with two bays, nave with three bays, north aisle with three bays, west tower with three storeys and transeptal vestry. There is a blocked medieval door in the south wall (now interupted by the western-most south window) and a medieval low two-centred doorway leading to the vestry. A plain, square headed west doorway (now blocked and featuring a plain square twentieth century doorway) dates to the late fifteenth century, and led to the tower. The tower's spiral stair is housed in a turret, and a recess in the nave west wall represents a doorway to it, formerly reached by a timber staircase. Its second storey was lit by two-centred light in the west wall (blocked after 1913). The tower's belfry stage has large, single, square openings in each wall, and the west one has been blocked. Its has a late fifteenth century crenellated parapet with twentieth century copings. The chancel arch is thought to date to the early nineteenth century, as is a blocked window in the north wall. The church was restored in 1860, at which time the north aisle and a vestry were added. A plastered ceiling was also added to the nave. The three-light east chancel window dates to this time, as does the single cusped lancet window in thecsouth wall. A blocked window in the north wall and the chancel arch are probably also nineteenth century. The vestry was rebuilt in 1924, to a larger plan, and a heating chamber was added underneath. The nave and north aisle floors were lowered at this time. A blocked fireplace in the vestry wall leads to a plain, square chimney. The reredos and panelled dado in the chancel are thought to possibly be twentieth century. The organ and pulpit date to 1935, and the oak stalls date to the mid-twentieth century.

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

N Vousden, RCAHMW, 16 October 2012