St Cynfil's is a small nineteenth-century church built on a more ancient site. It is located in a rounded churchyard, once used as a cemetery, on a bluff overlooking the marshes between Pwllheli and Llanbedrog. It was built in a Neo-Norman, Romanesque revival style in 1842 (replacing a thatched church) to the designs of the architect George Alexander who had worked in other styles in London and the West Country. It was constructed of granite rubble, now rendered, with diorite stone dressings, and with a slate roof between raised gables. It is a single-cell building with gabled west bellcote. The west door is round arched and set on nook shafts, with plain capitals, small round-headed lights on either side. On each side of the building are three round-headed windows, and a triplet of round headed windows at the east end, the lights separated by square columns as mullions, with the angles chamfered, and plain Romanesque capitals. A stone cross crowns the gable end. Attached to the north wall is a tall monolithic slab with relief coat of arms at its head, and inscribed to GRVFFYTH AP IOHN WYNN. G of the Penyberth branch of the family, who died in 1613 aged 79.

The west door opens into an internal lobby. Walls are plastered above a dado. The roof is of three bays supported on hammer beam trusses with arch braces to the collar. Fittings included an octagonal pulpit, simple pews, and an arcaded altar rail. The church is now redundant.

Commenting as part of the crowd-sourcing project Crwydro in 2014, Alan Fryer reported that the church had been recently 'converted to residential use, though the exterior remains unchanged, except for the loss of the ivy', further noting that 'The modern church at the adjacent Polish Home is named Kosciol pw. Matki Bozej i sw. Cynfila ? The Church of Our Lady and St Cynfil.'

(Sources: Cadw Listing description; R.Haslam, J.Orbach & Adam Voelcker, Buildings of Wales: Gwynedd (2009), p.492; Crwydro, 04.08.2014)
RCAHMW, 18.03.16, 03.04.18