St Michael's Church, Myddfai, is situated within a roughtly circular churchyard, whose south and east boundaries are delineated by a road. Three other roads also meet at this point. In 2005 RCAHMW aerial reconnaissance identidied a denuded curving earthwork bank in the field to the north of church, mirroring the curvilinear churchyard and indicating an original outer, oval enclosure. Current LiDAR data also shows an apparent continuation of this earthwork bank in the field to the north-west of the church, beginning at the north field boundary, immediately below the north-west corner of Bethania Chapel(NPRN 6610)'s curtilage and continuing as far as the opposite field boundary. The church was first metioned in documents of 1284. It has been suggested that it was constucted by an English family named Wroth, who forfeited the advowson in 1299. The church was a parish church during the post-conquest period, belonging to the Deanery of Stradtowy. In 1913 a damaged stone basin with lugs was noted at the east end of the north aisle. The basin was noted to have reputedly originated from the vanished chapel of Dol Hywel. Inside the church is a carved memorial to David Jones (died 1719) and John Jones (died 1739), famous physicians of Myddfai.

The church is a Grade I listed building, listed as a largely complete medieval church with an unusually intact interior, of a scale and detail unexpected in so rural a location. The church is constructed of mixed rubble stone (predominantly limestone), and consists of two-bayed chancel, wider four-bayed nave, two-bayed north chapel (same dimesions as chancel), four-bayed north aisle (same dimensions as nave), two-bayed lean-to vestry (north of aisle west bays), south porch and lean-to gas plant house (north of aisle and east of vestry). The nave and chancel are thought to date to the thirteenth to fourteenth century. The octagonal limestone font is thought to be fourteenth century in date. The north and aisle are thought to date to around 1500. The south porch and recess for a rood stair are thought to be early seventeenth century. The vestry is thought to date to the early nineteenth century, and is known to have been built before 1839 (although in 1866 it could only be entered from outside). Three sections of wall paintings are visible on the chancel walls, thought to date from the medieval period to the early nineteenth century. They include early fragments of paintings, 'words of institution' of the Holy Communion (early eighteenth century) and Decologue, Creed and Paternoster (early nineteenth century). The church was restored in 1874, although this was of low impact. Two west windows were added. The unblocking of the vestry north door and insertion of two heating soves in the nave and aisle may also have occurred at this time. Flues from the stoves led to chimney stacks in the side walls, which were removed in 1926. The church (mainly the vestry) was again restored in 1926, to the designs of Charles W. Mercer, Llanelli. The vestry was divided in two, with its west half excavated to form a below-ground heating chamber. Heating apparatus was installed, with the flue leading to a square chimney stack on the aisle's north-west corner (now removed). The vestry north door was rebuilt and two windows were inserted, one either side of the door. The lean-to gas-plant was also added at this time. The north chapel east bay floor was lowered, the two stoves and their stacks were removed and the nave butresses were built. The church was renovated in 1992, when the roofs were reslated, timber and plaster panels replaced and internal walls partially reskimmed.

Painted features include traces on the chancel arch and in the chancel, a repainted eighteenth century 'chosen sentence' and nineteenth century texts on stone tablets.

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

RCAHMW 2022