St Mary's church is situated on the east side of Mona Road, on a rocky knoll above the junction with Telford Road (A545). It was built in 1858 in Decorated style to designs of architect Henry Kennedy to replace the old church of Llandysilio (NPRN 43650) at a time when the local congregation was expanding. It is built of random rubble with sandstone dressings, continuous sill band and plinth, articulated by offset angled buttresses, and with a slate roof with stone copings. It consists of a three-bay nave, shorter narrower chancel with single pitched roof north transept (containing organ blower and vestry), west square three-stage bell tower with crocket finials, and steeply-pitched roofed porch on the south-west of the nave. The church is lit through reticulated traceried windows. Inside, the walls are plastered and painted. The nave roof is of six bays, the chancel roof of three bays, both with exposed collared trusses with cusped braces, carried down to wall posts and corbels with shield design on facing panels. The chancel is raised by three steps, the sanctuary is raised by a further two steps with a granite reredos (1885) of three bays across the east wall. Fittings include an octagonal granite font (1900) carved with floriate designs in quartrefoil recessess in each panel and set on circular granite columns with four pink marble outer columns topped by stiff leafed foliage; an octagonal pine pulpit with four facing panels with cusped carving to the upper part; and pitch pine pews and choir stalls. Stained glass windows, added later, include works by Mayer (1869) and ?Shrigley & Hunt (1876).
Sources:
Cadw Listing description.
R.Haslam, J.Orbach & Adam Voelcker, Buildings of Wales: Gwynedd (2009), p.197.

RCAHMW, 2 February 2016