St Hywel's Church is situated within a rectilinear churchyard. The site may be early medieval in origin. The benefice was held in multiple patronage (a pre-Conquest form of land tenure) by the Welsh tenants of the parish until it was purchased by the Bishop between 1280 and 1302. The church was a parish church during the post-Conquest period, belonging to the Deanery of Pebidiog. The advowson had been held in chief by the Crown, but in 1302 was appropriated by Bishop David Martin to the Chapter of St Davids Cathedral in order to provide three chantry priests to say Mass for the soul of the king. The appropriation was licensed in 1313, when the church (with Llandeloy Church) was appropriated for the provision of chantry and for services to the king, William de Valence and John Wogan of Picton Castle. St Davids 18 is a roman-letter inscribed quadrangular pillar of microtonolite. It is currently located in St Hywel's Church, Llanhowel (NPRN 102887). St Davids 18 (NPRN ), a roman-letter inscribed 5th- to 6th-century stone, is set upright against the west wall of the nave. It was removed here from Carnhedryn Farm, immediately south-east of a possible early medieval chapel and cemetery site (NPRN ), where it was in use as a gatepost at the west entrance of the farmyard.

The church is a Grade II listed building constructed of limestone rubble. It consists of 2-bayed chancel, wider 2-bayed nave, north transept with skew passage (occupying its entire east wall) and west bellcote. The nave and chancel may be contemporary and of 13th century date. The chancel arch has a rounded, 2-centred head with offsets denoting the former presence of a rood-screen. Three corbels just below the apex of the west face probably supported a rood-beam. The vaulted north transept and skew passage are thought to be 14th century. The gabled single bellcote is thought to date to the 14th-15th century. The nave south wall is thought to have been rebuilt during the 18th century. The church was restored in the later 19th century, when the windows and door were rebuilt. The church was also reroofed at this time.

Sources include:
Dyfed Archaeological Trust, 2000, Historic Churches Project, Pembrokeshire gazetteer
Dyfed Archaeological Trust, 2003, Early Medieval Ecclesiastical Sites Project, Pembrokeshire gazetteer

N Vousden, 4 January 2018