St Cynyr's Church, Llangunnor, is situated on a hill top, in an irregularly shaped churchyard, depicted as sub-circular on historic (1906) Ordnance Survey mapping. On Modern Ordnance Survey mapping the churchyard appears to have been extended to the north on its west side. An incised stone decorated with a Greek cross has been re-set in a recess in the church's porch. During the medieval period St Cynyr's was a parish church belonging to the Deanery of Kidwelly, and the advowson was reportedly in the hands of the lord of Maenor Cunnor. By 1833 the patron was the Bishop of St Davids. A well is depicted on historic Ordnanec survey mapping some 90m south of the churchyard and some 30m east of the old Vicarge.Two notable graves, belonging to David Charles (NPRN 309809), Calvinistic Methodist minister and hymn writer (1762-1834); and Sir Lewis Morris (NPRN 309810), poet, are located in the churchyard.

The church is a Grade II listed building constructed of limestone and Old Red Sandstone rubble. It is considered to have a distinctive Georgian-style interior. The building consists of two-bayed chancel (formerly north chapel), three-bayed nave (formerly north aisle), south chapel/vestry (former chancel), four-bayed south aisle, west porch with bellcote above, south vestry and coalhouse/boilerhouse east of vestry. There is an under-floor void. The limestone font is thirteenth century in date. The south aisle, formerly the nave, is also suggested to date to this time. The south chapel/vestry is thought to date to the fouteenth century, and the south wall fatures the vestry door, which is thought to possibly be a medieval priest's door. The nave, formerly the north aisle, is thought to be fifteenth century in date. The chancel's west bay and the porch are thought to be late fifteenth century in date, and the chancel's east bay is thought to be sixteenth century. There were two church bells of 1552 (although the present bellcote is single). Windows were repaired in 1810, and the porch door was replaced in 1813. The church was restored around 1815-1828, which may be when the arcade between the nave and aisle was demolished and replace with classical columns. The vestry is thought to have been added in the late nineteenth century, which may also be when the nave and chancel were moved to the northern half of the building. Some re-fenestration of the chancel and north chapel also took place at this time, and the south chapel was re-floored and the organ added. The passages and chancel were re-floored in the later twentieth century, possibly in 1962-1963, when minor restoration was undertaken to the designs of A.D.R Caroe, London.

A three panelled composition, though to date to the late eighteenth or early twentieth century, of the Lord's Prayer, the Decalogue and the Apostles Creed, in Welsh, were recorded in 1974.

Sources include:
Cadw, Listed Buildings Database
Cambria Archaeology, 2000, Carmarthenshire Churches, gazetteer, 48
Ordnance survey, 1906, second edition 25in
Richard Suggett, Painted Temples: Wallpaintings and Rood-screens in Welsh Churches, 1200–1800, (RCAHMW 2021).

RCAHMW 2022