Interior
Rubble stone walls inside. W end painted grained panelled doors in panelled infill to C15-16 segmental-pointed tower arch with inner arch dying into piers, ovolo mouldings. Boarded ceiling to tower, W door and window above in deep reveals with stone voussoirs. Nave W C20 organ loft. Broad 7-bay arch-braced collar-truss roof with windbracing and 3 tie-beams, all of 1869. Segmental pointed arch to S door with stone voussoirs, restored moulded rood-stair door to N with depressed-arched head and mural stairs up to former rood-loft door in NE angle. Chancel arch is broad segmental-pointed with 2 chamfers dying into sides, possibly pre-C15.
Chancel has 1869 roof of 3 bays with arch-braced collars and brattished wall plate. C19 E window has shafts. S side has C15 3-light and low S door with segmental pointed head of two stones. On N side, an exceptional 2-bay late C16 arcade to the N chapel with Tudor arches on octagonal centre pier. Arches are in 2 orders, with double recessed chamfers on chancel side, while N side to chapel has double wave moulding, on leading edges, and no hood mould. Pier has fluted neck with rope-mould above, below coved capital. Above arcade is a reset stiff-leaf corbel, possible C13.
NE chapel has broad roof, probably of 1869, with tie-beams, arch-braced collars and windbracing. E wall has marks of blocked window. W wall has blocked long opening to right of centre (former window?) and straight joint to far left, at original nave NE corner. Segmental-pointed W door with stone voussoirs, opening into C19 vestry.
Fittings: Remarkable ashlar font apparently made up of different medieval bits, the top is a shallow square bowl with ovolo top and angle mouldings, on a tapering lobed underside that does not appear to be of the same piece, the 8 lobes divided by raised fillets and the four cardinal lobes fluted, over a ring moulding. This stands on a panelled tapering octagonal shaft, on a moulded circular base. Rood beam Rev. J. Ward (d 1917). Mid to later C20 altar with painted carved panel of St Michael, panelled pulpit, pews and organ.
Stained Glass. Nave S first after 1945, Christ and woman full of good works; S second fine quality window by C.E. Kempe, 1901, to Augusta Stear (d 1899), SS Mary, James and John; Nave N, SS Ambrose and Augustine to H. Cromwell, (d 1901), richly coloured, also by C.E. Kempe. Chancel E Christ, SS Michael and Peter, to Capt. G.P. Steer (d 1915), 1916 by Kempe & Co. South 3-light, 1905 by Heaton, Butler & Bayne, Good Shepherd with SS Stephen and Lawrence, lesser quality.
Monuments: On NE chapel N wall remnant of elaborate C16 alabaster monument to one of the Morgan family, altar recess framed by side piers with fruit, shields and tablets, top piece with inscription (Philippians 1, 21), date 1590, and Morgan arms above. E wall has memorial to Lady Mary Blount (d 1657), ashlar with marble panels in pilasters and frieze, the Latin inscription repeated on a C17 brass plaque below; plaque to Maria Kemeys of Maendy (d 1798) circular on dark square panels, with draped urn above; large marble memorial to Martin Kuyck van Meirop (Dutch merchant d 1775 at Mynydd Mawr) sarcophagus plaque under black pyramid between urns, and with carving below plaque. Monument is set within a crude ashlar frame with side piers, arched head and keystone; marble plaque to R.B Bowling, barrister, died at Llantarnam Abbey 1859, by James of Newport; ashlar memorial to Amy George, 1728, with gadrooned shelf under plaque flanked by thin columns with crude leaf capitals, and ogee cornice. W wall has neo-Grec scroll to E.F. Blewitt of Llantarnam Abbey (d 1868) by A.H. James of Newport; neo-Grec plaque to Edmund Blewitt, barrister (d 1834) by Wood of Bristol and ashlar memorial to Mary McNamara (d 1791) with pilasters and broken pediment.
Chancel S wall memorial with urn and branches to Ann Williams, Mary Williams and Edward Walters (d 1829-34) by Davies of Usk; oval plaque in painted moulded frame with carved spandrels, to Henery (sic) Lawrence (d 1802); small urn memorial to Ann Jones (d c1760) over plaque to Blanch Jones (d 1804) by Drewett & Co, Bristol.
Nave N has memorial with flaming urn to M and H Phillips (d 1804 and 1808) by Jones, Dunn & Tyley of Bristol; painted plaque with rustic winged circular face, to Martha Absalom (d 1770); eroded plaque with hourglass in broken curved pediment and skull below, to Ann Dentt (d 1676); memorial to W. Williams (d 1836) with urn above and reversed torches, by T. Davies of Usk. Nave S has plaque with shell motif at head of carved border, to Henry James (d 1764); scroll plaque to Jane Johnson (d 1841), by Watkins of Newport; plaque to William Harris (d 1815) with pilasters.