'Edy' or 'Edi' is thought to represent a Celtic tradition rather than being a corruption of 'Edith'. St Edy's Church was a chapelry of the Deanery of Kidwelly in the posconquest period. There is an earthwork to the immediate south-west of the church. The remains of a possible outer enclosure (most clearly visible on Historic Ordnance Survey (1879), where it is partially dilineated by a track some 100m north-west of the church) can be traced on modern and historic Ordnance Survey mapping. The church hall (NPRN 23322) is situated some 25m north-west of the church building, adjacent to the north churchyard boundary. The church was a parish church in 1998, belonging to the Rural Deanery of Dyffryn Aman in the Archdeaconry of carmarthen.

It is now thought that nothing remains of the medieval church, although the base of the tower may be medieval. There was one bell present in 1684, which had been replaced by 1749. A south porch was present by this date. The present church is a grade II listed building, dating to the late eighteenth and nineteenth centuries. It is constructed of local rubble stone and consists of three-bayed nave, two-bayed chancel, transeptal mortuary chapel (north of chancel west bay), three-storeyed west tower, vestry over boilerhouse and south porch. The tower's first and second storeys are thought to date to around 1800. Its first stage has a blocked west door. The mortuary chapel is thought to date to the eighteenth century. The tower was noted to be whitewashed in 1820-1821. The church was substantially rebuilt in 1860, to the designs of R.K Penson. The chancel, nave, proch, vestry and boilerhouse all date to this rebuild. There is a plain, square chimney in the south chancel wall. The belfry is also thought to have been added at this time.

Sources include:
Cadw, Listed Buildings Database
Cambria Archaeology, 2000, Carmarthenshire Churches, gazetteer, 48
Ordnance Survey, 1879, first edition 25in
Ordnance Survey, modern, 1:10,000

N Vousden, RCAHMW, 22 January 2013