The old St David's Church was a parish church during the medieval period, belonging to the Deanery of Carmarthen. The church may have been a collegiate chapel appropriated to St Davids Cathedral, but is has been suggested that the collegiate chapel was in fact located within the later Bishop's Palace (now Carmarthen Museum). Abergwil had three dependent chapelries at Llanfihangel-uwch-Gwili, Llanllawddog and Llanpumsaint. In 1833 the parish was a discharged vicarage in the patronage of the Dean and Canons of Windsor and the advowson belonged, by courtesy, to the Bishop of St Davids. In 1998 St David's was a parish church in the Archdeaconry of Cardigan, Rural Deanery of Carmarthen. In 1917 a broken sepulcharal slab with carved cross was noted in the floor of the new church. The slab, thought to date to the thirteenth century, was reportedly found in the churchyard.

The church consisted of north nave and chancel, south aisle (divided from nave by a four-bayed arcade of pointed arches on octagonal piers), south porch at the west end of the south aisle, transeptal structure at the east end and double bellecote at the nave' s west end. The church was replaced with a new church (NPRN 117057), on the same site but immediately to the north, in 1840-1843. A sixteenth century coffin lid, located within the church, was destroyed at this time. 1889 Ordnance Survey mapping depicts the building some 30m further west than 1906 and modern Ordnance Survey mapping.

Sources include:
Cambria Archaeology, 2000, Carmarthenshire Churches, gazetteer, 48
Ordnance Survey, 1889, first edition 25in
Ordnance survey, 1906, second edition 25in

N Vousden, RCAHMW, 7 January 2012