The church has an exposed roof. The chancel retains 6 arch braced collared trusses on wall posts down to shaped purlins, dating to the extensive rebuilding of c1500, and contemporary paired purlins with cusped windbraces; the 4 trusses to W are similarly detailed but not as heavy as those to E and have a more rounded soffit, the angled braces above the collar are cusped.
Most of the interior dates to the mid C19 rebuild but retains a C17 rood screen which has 3 bays to each side of a central opening, the bottom part is boarded, the upper rail supported on shaped balusters with a carved naturalistic frieze above. The screen is thought to have been rebuilt in C19 and the tracery below the upper rail added. The chancel is raised by 2 steps and the sanctuary a further step with a moulded rail on twisted stanchion with floriate brackets; there is a small piscina set in a trefoil headed recess in the S wall of the sanctuary and entry to the N vestry is through a chamfered pointed arched doorway in the N wall of the chancel. The floor of the sanctuary has encaustic tiles and the vestry has a modern stone floor in which there is a memorial stone to Ellis Wynne of Lasynys: rector of the parish in the early C18. The octagonal pulpit is built of dressed stone on a stepped raking plinth with trefoil headed recesses at the angles. The C16 octagonal font is to the W end of the nave and there is a rough stone water stoup set into the N wall. The pews are simple C19 box pews and there is a simple chamfered screen to the W end of the nave.
All of the glass dates to the mid C19 rebuild, the E window bears depictions of Christ at nativity, crucifixion and ascension; in memory of Edmund Prys, Archdeacon of Merioneth, 1858. The central window in the S wall has 4 portrayals of Christ and is in memory of Ellis Wynne, d.1735.
Memorials: At the W end of the N wall has a restored slate slab to the Owens of Crafnant, 1520. to its right another slab to the Owen family in the C18 commemorating the children of the family of John (d.1783) and Anne Owen (d.1778): William d.1757, Anne d.1758, Robert d.1770, Elizabeth d.1770, Owen d.1775, Maurice d.1778 and William c.1783: Erected by a surviving son, John, in 1822.
Further E on the N wall is a marble memorial, also to the Owen family of Crafnant: to Elizabeth, wife of John Owen, d.1834. Below this memorial there is an ornate carved wooden tablet.
Towards the E end of the N wall of the nave are a further pair of marble memorials, the first to John Richards of Llanfair Isaf d.1829 and his wife Jane d.1847, also their 3rd son David and his wife Jane d.1828; the second to Gwen, wife of R H Richards, also of Llanfair Isaf, d.1841.
On the S wall are several C20 memorial tablets and a wooden trefoil headed board which lists the rectors of the parish to the present day.