Interior
The porch has a heavy ribbed ceiling with deep square panels. The pointed nave doorway has continuous roll and keeled roll mouldings, and a hood mould with head stops. The boarded door has strap hinges. The similar boarded door to the stair tower has a shouldered lintel.
Nave and chancel have ashlar walls with red-sandstone banding. The 7-bay nave roof has arched-brace trusses on corbelled wall shafts, and a band of trefoils above the wall plate. The 2-centred chancel arch has an inner order on corbelled shafts with stiff-leaf capitals, hood mould and head stops. The chancel has a wooden rib vault on foliage corbels carried on ringed shafts rising from a sill band. The sill band is carried as a hood mould over a S doorway and a pointed S transept arch. On the N side the sill band is carried over a pointed vestry door. In the sanctuary, rere arches have ringed marble shafts, moulded capitals and keeled and roll mouldings to the arches. The SE and NE bays have cusped arcading below the sills, and the E bay has a reredos comprising a painted foliage band over a stone ledge. In the S bay is a recess below the window for a priest's seat. A N aumbry has 2 cusped arches and foliage spandrels. The intarsia pavement is an addition of 1909.
The ornate font has a square bowl, each face having 3 panels with foliage and quatrefoils in relief. The octagonal stem has 4 detached shafts, with stiff-leaf capitals around the underside of the bowl. The square base has an inscription to J. Henry Venables (d 1866). The wooden font cover has a scrolled pyramidal ironwork canopy. The polygonal freestone pulpit has cusped niches with marble shafts, figures of SS Llyre, Paul, John the Baptist, Peter and Afan, and a ballflower frieze below the cornice. Pews are plain, but the choir stalls have ends with poppy heads and foliage carving, and open cusped arcading to the fronts. The communion rails are brass.
In the N wall is a large wooden war-memorial plaque, with flanking attached pinnacles and brattishing, by W.D. Caroe. Other monuments are relatively simple. At the E end of the S wall are 4 brass plaques by Hart, Son, Peard & Co of London, to Richard Venables (d 1894), George Venables (d 1888), Joseph Venables (d 1866) and Richard Venables (d 1858). In the nave E wall, S of the chancel arch, are war-memorial brass plaques to John Lister Dillwyn Venables Llewellyn (killed 1917) and George William Dillwyn Venables Llewellyn (killed 1940). A brass plaque at the E end of the N wall commemorates the first vicar of the church, John Lloyd (vicar 1883-1902) by C. Hay of Brecon. Above it is a brass plaque to Thomas Rawstone (killed Ypres 1917). In the N respond of the chancel arch is a brass plaque to Ronald Hunter (d 1905) and Edward Williams (d 1915). Members of the Dillwyn-Venables-Llewellyn family (d 1951-76) are commemorated in a plaque in the S respond.
Most windows have stained glass by C.E. Kempe. Glass in the sanctuary forms a complete iconographic scheme from Biblical Patriarchs to Celtic saints. In the N window are figures of Noah, Abraham and Moses; in the NE window Isaiah, King David and John the Baptist; in the E window Christ and SS Mary and John; in the SE window SS Mary Magdalene, Peter and Stephen; and in the S window SS Llyre, David and Afan. Nave windows mostly depict New Testament scenes. In the S wall the 3 windows depict 'Fear not Zacharius' and 'Behold the Lamb of God', Annunciation and Nativity, and 'Blessed are the Poor in Heart' and St Ceclia. In the N wall the 2 windows depict the Crucifixion and the risen Christ on the road to Emmaus. The W window, by Heaton & Butler of London, has figures of Aaron, Moses and Joshua. In the porch E window are figures of St Cecilia and St Timothy with St Eunice, post 1908.