St Mary's Church, Llanfair Talhaearn, was founded as a cell by St Talhaearn in C5th.  It was first mentioned in 1274 and substantially restored by J. Oldrid Scott in 1876, who replaced much of the early work. It is a double-naved parish church of local rubble stone with sandstone dressings, and has a slate roof with C19th slab-coped and kneelered gable parapets, surmounted by gable crosses. The south porch is probably of C17th origin but was replaced in the C20th.

The twin-naved interior is of continuous nave and chancel plan. There are 9-bay arched-braced collar truss roofs to both chambers, with two tiers of small cusped wind braces. There are simple fixed C19th pews, and a boarded and stone-flagged floor, as well as a 6 bay pointed-arched arcade with octagonal columns. The font is in transitional style, with an octagonal sandstone basin. There is also an early English style C13th font bowl, which is now unused but has waterleaf carving to its chamfered corners. A table of benefactions dating to 1717 is painted in oils on a wooden panel.

A plain octagonal pitch-pine pulpit has simple blind tracery, and a baptismal tank, constructed in 1849 for adult immersion, is in the north-west corner. There are simple pine choirstalls with poppy headed pew-ends, and polished wooden altar rails with Gothic wrought iron scrolled supports. There is fine figurative stained glass in a window of c.1880, and an organ of 1880 by Peter Cronacher and Co. Huddersfield.

Sources include:
RCAHMW Wallpaintings database. 2004.09.10/RCAHMW/SLE
Richard Suggett, Painted Temples: Wallpaintings and Rood-screens in Welsh Churches, 1200–1800, (RCAHMW 2021).

RCAHMW 2022