The site of St Teilo's dates back to the late fifth century but the fabric of the current building seems to be late twelfth- or early thirteenth-century. Although the parish of Bishopston, of which St Teilo's was the parish church, was in the Diocese of St David's, the church remained under the authority of the Bishop of Llandaff from 1130 until disestablishment in 1920. The church underwent several renovations, including restorations in 1851, by Thomas Penrice of Kilvrough when the porch was added, and 1927, by W. D. Caroe when restoration of the roof revealed a fifteenth-century oak hammerbeam roof and two windows of the thirteenth- and fifteenth-century were reopened. The current church consists of a nave, chancel, south porch, and west tower and is constructed of rubble stone under stone tile roofs. The nave is long and narrow with two raked buttresses added to the north wall and one added to the south west angle. One of the buttresses on the north wall butts onto a low, round-headed blocked doorway. Similarly, there is a blocked priest's door with a two-centred head in the south wall of the chancel. The door in the porch is round-headed and contains studded and panelled double doors. There is also a narrow doorway in the west of the tower containing nineteenth-century studded and panelled double doors within a pointed arch under an overlight with quarries. The tower has a corbel table with embattled parapets within which is a pyramidical roof with cupola. The belfry is pierced with lancets and houses two bells dated 1713 and 1714. The nave and chancel have several windows in the Early English style. The eastern window of the chancel is a three-light Perpendicular-style window with a hoodmould terminating in headstops. The window within depicts the Crucifixion. It was the first stained-glass window to be placed in the church and commemorates seven men from the parish who died in the First World War. Inside, most of the furnishings, including the choir stalls, alter rail, pulpit, and organ, are early-twentieth-century, installed as part of the 1927 renovation. The shallow-pointed chancel arch is, as is common in Gower churches, asymmetrical. There is a massive square medieval font on a round stem, as well as a square piscina on the south wall of the chancel. To the right of the piscina is a marble mural tablet with folate decoration in relief in memory of the Rev. Edward `Celtic? Davies (1756-1831), author of `Celtic Researches? and `The Mythology and Rites of the Ancient Druids? who was rector of the parish for twenty-five years. Outside of the church are the remains of a churchyard cross (Nprn 305584) consisting of a square socket stone set upon a square block on a low mound.

(Sources: Orrin, The Gower Churches (Swansea: 1979), pp. 27-30; Cadw site report)
A.N. Coward, RCAHMW, 17.04.18