The porch has a 2-bay arched-brace roof with a single tier of windbraces, of reused materials. The N doorway has a continuous hollow moulding and double doors with iron studs.
The interior has a short nave and a broad crossing which structurally is integrated with the N transept. Walls have exposed coursed stone faces. The nave has a late medieval 4-bay arched-brace roof with 2 tiers of windbraces, and a small bullseye window over the crossing arch. The tower arch has a continuous hollow moulding to a 2-centred arch. Above it are 3 stepped cusped lights under a segmental arch, and with sill band. Two small stoups are in the N wall. The 4-centred crossing arch is inscribed with date 1894. The crossing and N transept have a late medieval arched-brace roof similar to the nave, with windbraces and boarding behind, of which 4 bays are late medieval and the 2 narrower bays at the N end were added in 1775. The S transept has a late C19 roof of closely-spaced arched braces. All the roofs have wooden cornices. The chancel arch, also of 1894, has hollow-moulded polygonal responds, moulded capitals and a 4-centred arch. On its L side is an arch behind the pulpit with an inner order of cusping and outer order of shafts. The chancel has a shallow-pitched 3-bay king-post roof with corbelled brackets and a cornice with quatrefoil frieze. On the N side of the chancel is a 4-centred arch to the vestry (now housing the organ), to the E of which is another but wider 4-centred arch to the NE chapel. The chapel retains its original 2-bay arched-brace roof with cusped windbraces. The tower has a newel stair.
The chancel has a late C19 stone reredos, and a C14 trefoiled piscina. Another slightly later piscina, with cusped ogee head and corbelled basin enriched with relief foliage, is in the S transept. In the S wall of the S transept is a C14 cusped tomb recess under a crocketed ogee hood and flanking attached pinnacles.
The plain octagonal font on a pedestal is C15. The corbelled polygonal wooden pulpit has Gothic panelling and is late C19. Across the chancel arch are wrought iron double gates with flanking railings on a stone dado, enriched with scrollwork. Choir stalls have open arcading to the front, and rounded backs to the back row.
The NE chapel has a large alabaster tomb of William Gruffydd (d 1587) and his wife Margaret (d 1593), daughter of John Wyne ap Meredydd. They lie in contemporary dress on a large tomb chest with weepers to the sides between fluted pilasters enriched by coats of arms in relief, and with an inscription around the rim. In the reveal of the E window, against which the tomb is placed, is an heraldic alabaster tablet in relief with the date 1593. The vestry has, above the E doorway into the NE chapel, a small child's effigy built into the wall in a dressed surround that was probably re-used from a window. In the nave are 2 medieval grave slabs built into the S wall. The transepts have numerous C18 wall tablets, while the chancel has brass memorial tablets.
Several windows have late C19 or early C20 glass. The E window is by Mayer & Co of Munich, probably from their London workshop, and portrays Christ with the Apostles. In the chancel SE window is the miracle of loaves and fishes, by John Hall & Son of 1912. The chancel SW window is unsigned and has no clear subject matter, but shows, in late-medieval style, the sacrifice of a lamb, harvesting grapes, pouring wine and the death of a priest. In the S transept the S window depicts 'Come unto me all ye that labour', also by Mayer & Co. The N transept depicts 'suffer little children' by Lavers & Westlake of London, dated 1894. In the nave, the SE window depict SS George and Margaret, and commemorates Morys Wynne Jones, killed in action in 1914. The nave SW window, also unsigned, shows Christ calming the storm at sea.