An attractive old church set back from the main road [ A525 ] in the centre of Llanfair-Dyffryn-Clwyd. The church is surrounded by lawns, which on their edges have several Victorian graves which are over grown. It suggests a more extensive grave area in the past. At the rear of the church is a more formal graveyard which contains graves from circa 1910 onwards.

The following has been taken from the web:

History

A church here is mentioned in 1254 as ecclesia de Lanweyr. A chaplain, Howell, is mentioned in 1295; from 1412 there were sinecure rectors and there have been vicars from 1575. The original dedication was to St Cynfarch, thought to be a C6 or C7 North Wales chieftain. The present church is a C15 rebuild, given an additional dedication to St Mary. Older monuments incorporated in the present building are a sepulchral slab of the C14 now in the chancel and remnants of a C14 slab seen in the blocking of the north door. The detailing suggests an equal status given to the two naves, which were and still are of identical size and height.

Before the C19 restoration of the church the date 1503 appeared in the stained glass of the east window, and although this glass has been relocated in a south window in mixed condition it can still be found. The east window suffered sacrilegious damage in 1586. The masonry of one south window is dated 1626, and the bells in the tower are dated 1631 or later. A small stone-built porch was added at an unknown date. The church was later given ceilings following the curve of the arched braces of the roofs. When Glynne saw the church in 1849 he described the exterior as whitewashed.

St Mary's was restored for the Rev. Basil Jones in 1870-72 by John D Sedding, architect, of Bristol, at a cost of about £2300; a brass commemorative plaque with the date 1872 appears over the main door. In Sedding's restoration the walls were raised 0.6 m and the exterior whitewash removed; the ceiling and a west gallery in the south nave were removed. The roof was reconstructed and re-exposed using the original timbers. There were a new altar, reredos, stalls, screens, pulpit and font, retaining the north nave as the principal nave, and a new porch. Part of the rood screen survives in the south nave, with copied carpentry in the north nave. The old altar and pulpit were removed to another building (the Jesus Chapel). Later work included the formation of a vestry in the west of the north nave. In 1949 the east end of the south nave was formed into a war memorial chapel.
Exterior

A large church characteristic of the double-naved layout favoured in the Vale of Clwyd. The masonry is mainly the local limestone, axe-dressed and coursed, with some admixture of sandstone. The tower masonry and the C19 restorer's masonry at the heads of the walls and in the renewed buttresses at the east end is in similar limestone. The roofs are slate with tile ridges and stone finial crosses.

The blocked north doorway is in local sandstone and has a four-centred chamfered arch; it was blocked in the C19 restoration with monumental stone fragments. All the windows are four-centred, having been renewed in the restoration or given new tracery following their original designs. The south door, within the porch, was redesigned in the restoration. The east window of the nave is of five main lights, with quatrefoil panels at the foot; early grotesque heads were retained as finials to the label mould. The east window of the aisle is much smaller, of five main lights, featuring brattished transoms; the second window on the south side is similar. The first window to the south is in four main lights with ogee heads. The other windows are of three lights.

Interior

The interior consists of a main nave and a south nave of equal size, separated by an arcade of six arches. The arches are of two orders, chamfered, on octagonal columns. Both have similar C19-reconstructed roofs of seven bays, using original timbers, plus a celured part of barrel shape over the chancel of each. The trusses have high collars, arched braces, and quatrefoil and trefoil apertures at top. The celures have decorated longitudinal fascias and close-set lateral plain ribs. The floor is of red quarry tiles laid diagonally, plus Goodwin's encaustic tiles in the chancel and sanctuary of the main nave. The pews throughout are in a plain Gothic style with very little decoration.

Both chancels are defined by a single step and a low oak Gothic screen, that in the south nave being a remnant of the rood screen. The pulpit and choirstalls are C19 Gothic, the panels pierced with miniature tracery, conforming to the style of the rood screen remnants. The reredos is a frieze of ogee-headed panels said to be alabaster, now painted; it has a cross at centre flanked by the Archangel and the Virgin. The altar rails are of brass on bronze decorative standards, and have a removable centre section instead of a gate. There are no stalls in the chancel of the south nave: here the east wall is panelled; the altar rails are of oak, also with a removable centre section. A brass plaque against the east wall records the formation of the war memorial chapel here. A low oak screen in the first bay of the arcade separates the two sanctuaries. Each has a C19 aumbry at right, that of the main altar being ogee-headed.

Mediaeval glass from the east window, including a fragment indicating the date 1503, is preserved in mixed condition in the second window on the south side. The east window now has a large representation of the Crucifixion with angels in the top lights and the Last Supper beneath (to John and Mary Puleston, 1872). The first window on the south side shows St James, St Mary, St John and St Winnifred, with scenes of the Nativity beneath, by Kempe (Wynne and Goodrich families, 1890). The first and second windows on the north side are to members of the Preston family of Llwyn-ynn. The first is by Westlake, 1873, showing the risen Christ; the second shows St Anne, the Virgin and Child and St Elizabeth, dated 1880. West of the porch is a window by Whall, 1893, with Christ and children, with its side lights filled with earlier flowered quarries. The other windows have textured and coloured glass.

St Mary's has a good set of wall monuments. The earliest is to Thomas ab Rice [1582], at the west, with a coat of arms, and a later monument of the same family above. Against the south wall is a monument inscribed in Latin, with an eared architrave and rounded pediment, erected by the prominent Jacobite Sir Watkin Williams Wynne to commemorate his former teacher, the Rev. Henry Price [1748], headmaster of Ruthin school, who also resisted the Hanoverian succession. To the east on the north wall is a Gothic alabaster monument to Sir John and Margaret Puleston [1908].
In the floor of the north chancel, north of the altar, is a slab to David son of Madoc: a shield charged with a leopard and roses, in front of a drawn sword [mid C14]. In the south nave there is a fine late-mediaeval parish chest.