Plastered interior with restored but apparently late medieval panelled barrel roof of 11 x 6 panels, moulded wallplate, moulded beams and ribs, open panels with exposed rafters. Ashlar later C19 four-bay N arcade of octagonal piers, big moulded capitals and bases, pointed arches with hoodmoulds and three carved flower stops. W end has narrow pointed tower arch with C19 ashlar in head, corbelled out from jambs, c1900 timber tower screen with leaded glazing. S side has 4 Y-tracery windows. Nave has cream tiles to floor. Broad later C19 ashlar pointed chancel arch with inner arch on column shafts, small ashlar pointed arch to left infilled with painted organ pipes. Chancel has plain plastered pointed roof and coved cornice, possibly earlier C19, later C19 patterned tiled floor and steps up to altar with brass altar rails. N wall opening for organ and pointed vestry door to right. N aisle has pointed panelled roof in 4x11 panels with moulded ribs and cornice. E end has later C19 opening with ashlar moulded pointed head and plain ashlar jambs, infilled with painted organ pipes. W window is column-shafted with hoodmould. Tower base has pointed medieval S door.
Fittings. Ornate white limestone carved pulpit of 1872 on green marble squat column shaft. Five-sided top with Gothic low-relief patterned carving, three with vesica-shaped panels two with latticed patterns, carved floral cornice. Ashlar low curving steps. Ornate alabaster and marble font of 1909 by Arthur Grove, tapered octagonal bowl with inscription to Rev. L. Jones vicar 1877-99 and roundel cross infilled in lapis-lazuli. Octagonal shaft with four column shafts. Unusual painted wood Symbolist font cover with gold domed temple on a silver stepped ziggurat with red angel each side, the ziggurat standing on a green sea with fishes. The font cover hangs by a chain from a dove. Similar main altar probably also of 1909 in alabaster with marble panels outlined in chequered mosaic and with centre lozenge panel with cross, lapis lazuli infill. Surround possibly later, plain marble side piers and reredos with central 3-sided niche, and brattished purple marble thin top cornice carrying gilded openwork cresting with two angels and chalice over centre, the cresting and possibly the whole reredos of 1960. Gothic oak panelling with blind tracery each side, earlier C20. Brass later C19 standards to altar rails with twisted shafts and Gothic scrolls. Oak later C19 stalls with carved bench ends and open traceried panels. Pine later C19 pews. Gothic chairs possibly earlier C19 but given 1917-18, 2 on chancel N, 3 on chancel S, and row of six and a half under tower. Organ on chancel N side with painted pipes, and minimal Gothic case, made 1868 enlarged 1883.
Memorials: W end alabaster ornate late Gothic frame to marble plaque to T.S. Sutton of Glynleiros (d 1896) and ashlar Gothic crocketted memorial to E.Sutton of Glynleiros (d 1872). Nave S neo-Grec sarcophagus memorial to J. Edwards Vaughan MP of Rheola (d 1833), by P. Rogers of Swansea. Four marble plaques: to W. Gronow of Court Herbert (d 1830) by Tyley of Bristol, to Mary Ann Gronow (d 1832) by H. Hopper of London, to Edward Hawkins of Court Herbert (d 1816) and to Sir RJA Kemeys of Ynysarwed (d 1832) by Reeves & Son of Bath. Chancel N has plaques to M. Fredericks (d 1859) by P. Rogers; to D.A. Bowzer (d 1814) Adamesque draped urn by Tyler; neo-Grec plaque to Mary Place of Glynleiros (d 1836), plain plaque to John Place Sr and Jr (d 1821 and 1823); plaque to Sarah Place by Bowen of Cadoxton; brass plaque to T. Leyson of Penscynor (d 1881); brass to RWN Leyson (d 1912) aboard RMS Titanic; fine neoGrec memorial with portrait relief to Lt Col R. Place (d 1828) by J.Ternouth; plaque with draped urn to W.Place (d 1828) and C.P. Jones Place (d 1847). Chancel S pedimented memorial to Jane Llewelyn (d 1766) with cherub below; painted plaster early C18 ornate armorial plaque; shield plaque to M. Williams of Dyffryn (d 1844) by Reeves; fine memorial to John Llewelin of Ynysgerwyn (d 1758) in grey marble shouldered surround with scroll pediment and arms; ornate early C18 memorial with crude Corinthian columns, cornice and broken curved pediment with arms, to the Llewelyns of Ynysgerwyn (1696-1722). Chancel W wall plaque with Adamesque urn, to ?Kemeys; fine Coade stone plaque to Thomas Williams (d 1802) with mourning woman, signed Coade & Sealy. In vestry two painted board memorials to Jane Williams of Dyffryn (d 1726) and to Rose Williams (d 1680) with rhymed inscription, brass plaque to the Williams family to 1729. N aisle W plaque to Francis family (d 1769-1798); incised plaque to R. Francis (d 1764) signed RP. N aisle N carved plaque with grape and passion flower to the Jones of Rockfield (d 1872-86); neo-Grec memorial to NW Edwards Vaughan of Rheola (d 1858) by Skelton of York; Michael Allen of Rockfield (d 1838) mixed neo-Tudor and Greek; marble plaque to Pendrill Charles (d 1857) by Cade of Bristol; plain plaque to G. Vaughan of Rheola (d 1844) by Rogers of Swansea; painted wood plaque to E. Tennant of Cadoxton lodge (d 1851). N aisle E fine Della Robbia ware coloured ceramic plaque to Daphne Tennant (d 1908), ornate late Gothic style stone surround to plaque to George Tennat (d 1832). Marble open book to C. Tennat (d 1873) by Perry, Lewis & Morris of Swansea.
Stained glass. Nave S second, colourful, Christ after the resurrection, to C.A. Thomas of Rockfield (d 1903). Nave S third good High Victorian glass of Christ and children to G.B. Williams of Aberdulais (d 1863). Nave S fourth faded bright coloured glass of Sacrifice of Isaac and Good Samaritan, to Evan Evans (d 1871). East window of Road to Calvary, Ascension and the Angel at the Tomb, brightly coloured, to N. Edwards Vaughan of Rheola (d 1868) by Arthur O'Connor. S chancel lancet, patterned C19 glass with chalice. N aisle W good Lamb of God window to Rev D. Griffith (d 1875). N aisle first Faith, Hope and Charity by Mayer of Munich to C.Jones of Rockfield (d 1897); second and third Christ in Temple and Gethsemane, High Victorian Gothic of quality, to R.H. Miers of Ynyspenllwch (d 1870).