Stone flagged floors, whitewashed walls, stone arcade between two halves, late medieval panelled barrel roofs to both naves and both chancels.
South nave has roof of 12 bays, longitudinal ribs missing, lateral ribs bead-moulded and stopped before bosses at former intersections. Bosses mostly replaced 1992, some original. S wall has big arched recess with C19 window, the recess originally for the rood stair, lit by the two small medieval windows to left. Plastered pointed chancel arch on plain stone piers with chamfered edges and plain caps. Affixed earlier C19 stone Creed and Lord's Prayer panels, with Ten Commandments panel adjoining on chancel S wall, reeded stone frames. Chancel roof 5x6 panels with run-out mouldings. Small whitewashed Tudor-arched recess on S wall, cambered head to one window reveal, straight head to the other. Between chancels is a broad Tudor-arched opening with double chamfer stone arch, half-octagonal piers, moulded caps and bases. Between the naves a four-bay stone arcade with double-chamfer pointed arches on octagonal piers with moulded bases and caps.
N nave has panelled barrel roof of 16x6 panels, mouldings without stop-chamfers. Medieval stone pointed chancel arch, double-chamfer, on half octagonal piers. N chancel has 5x6 panels to roof. E end divided off as vestry by 1874 screen.
Plain medieval octagonal font in conglomerate stone, on matching splayed octagonal base. A displaced medieval stoup is stored in N vestry.
Fittings: Of 1874 the pine pews, pulpit, reading desk, altar rails and vestry screens. The rails have open quatrefoil panels with wrought iron inserts. Encaustic tile flooring in chancel.
Memorials: In S chancel plain plaque to Rev J Price d 1819 by D Beynon of Cilycwm. E wall very fine marble memorial to Erasmus Williams of Llwynywormwood d 1785 by Thomas Paty & Sons of Bristol, with festooned pilasters, and top urn on finely carved pedestal with scroll abutments. In N nave Ann Price of Williamsfield d 1835, grey and white marble with large well-carved urn, by Thomas & Son of Brecon; Rev Lewis Williams d 1843, also grey and white marble, with cherub head in clouds, by Thomas & Son, Brecon. In N chancel some lettered floor slabs including one to Thomas Rice of Gorllwyn d 1691 and one to Henry Owen d 1727, referring to his Civil War ancestor Bishop Owen. On N wall monument to Magdalen Price of Porthyrhyd d 1829 by J Thomas & Son, Brecon, with small sarcophagus urn. In N vestry plain plaques to Jenkin Phillips of Blaenyddol d 1797 (tablet of 1854 by Noble of London) and Gwenllian Bishop d 1841 by Pollard of Taunton. Slate plaque with cherub head to Elizabeth Jones of Penyrhoc. Marble oval with Greek urn to Magdalen Price d 1831. At W end of S nave J Pryse Bishop d 1892, draped oval plaque, Charles Bishop d1886, scrolled angles, and Lt Arthur Bishop d 1864, plain oval signed J Edwards, London. A fourth to John Bishop 1831 also by Edwards has fallen and been removed.
Hatchment: Painted C19 Holford coat of arms on N nave wall.
Wall painting: Tiny fragments of wall painting exposed on N chancel N wall and to right of S chancel arch. Black letter text on S chancel E wall.