St Thomas's Church, Neath, is a late 13th century foundation of St Thomas the Matyr, re-named St Thomas the Apostle at the Reformation, it has an aisled nave with a west tower of c1340 which was raised in 1691.The nave was largely rebuilt and aisles added 1730, and there was a general restoration in 1874.

The three stage west tower is constructed of rubble with freestone dressings, first and second floor bands, stepped diagonal buttresses and regular quoins. There is a crenellated parapet on corbels, waterspouts to the corners and a clockface to the west. It has two light cusped openings to the bell stage elevations, over which are returned labels with stops, with a tall, pointed window over the west door with a returned cusped hoodmould, 4 light transomed panel tracery and hollow chamfered reveals. there is a further returned label over the door, which has roll moulded reveals, a 4 centred arch, plain spandrels and late 19th century doors.

The five bay, aisled nave has scribed plaster on rubble, an m-shaped slate roof and oversailing eaves. There are doorcases of 1731 at the west end of the north and west elevations of the aisles which have stepped architraves and keystones, moulded flat hoods on brackets and 19th century, 6 panel doors. There are two-light, Victorian, round headed, geometric windows. There is an early 19th century vestry in the southeast angle with the chancel, built of coursed rubble with dressed quoins and a gabled slate roof. This is lit by a 24 pane sash window, with a round arched doorway offset to the right. There is a Venetian window to the east end of the chancel which has a moulded, returned hoodmould with toothed ornament. The alter rails are early 18th century, with cannon barrel balusters, while the rederos is 19th century and originally from St Davids Church, Pelas. Rectangular arcade piers rise to plain round arches, the tops of the piers having moulded capitals with toothed ornament. The nave roof is 19th century, being boarded arch braced trusses, with there are plastered aisle ceilings, a moulded cornice to northern aisle. There is a fine Royal Arms of 1731 on boards with a pediment to the east wall of the north aisle, and a wall monument of 1794 to Sir Humphrey Mackworth in the south aisle. This has a draped sarcophagus bearing an urn, on a podium with pilasters and family arms of gilded marble. There are numerous other monuments, a baluster font with gadrooning to the bowl, and beneficiary plaques to the aisle walls and arcade piers, mostly of 18th century date. There is a 10th century incised wheel cross fragment formerly in Llanilltyd churchyard by the doorway at the west end of the south aisle.

The boundary wall is early 19th century, constructed of narrow, regular courses, with tall, slender, rusticated dressed stone, gatepiers with crenellated Gothic limestone caps. There is a cambered ironwork overthrow, with scrolled insets bearing a central lantern bracket with finials. The ironwork gates have palmette-like finials and dogbars. There are stone steps up from the roadway.

Sources include:
Cadw listing description
Richard Suggett, Painted Temples: Wallpaintings and Rood-screens in Welsh Churches, 1200–1800, (RCAHMW 2021)

RCAHMW 2022