The church has a fifteenth-century west tower, north porch and vestry, nave, and a chancel with late thirteenth- or early fourteenth-century windows, much restored in 1848. The remains of the church of St Mary can be seen in the eastern part of the large churchyard.

There is an interesting collection of fifteenth-century fragments in a south nave window (sIV) said to be original to the church. ¹ There are, however, no antiquarian records relating to the glass. From the glass itself it can be seen that there were here originally a number of figures of male and female saints, some highly unusual. Of the former there is evidence for St Gregory the Great, St Arnulphus of Soissons, St David and St Lawrence, and of the latter, for St Barbara, St Mildred and St Petronilla. ² For two of these, reasons for their presence here may be suggested. Aymer de Valence inherited the manor of Stiffkey, and on his death in 1323 it descended to David de Strabolgi, Earl of Athlone, and later to the 2nd and 3rd earls, both called David. The saint depicted may thus have been St David of Scotland, rather than St David of Wales. Similarly, a later lord of the manor, John Halsham, who presented to the church of St Mary here as lord in 1413, married a lady called Petronilla. At Cley, a few miles east, St Petronilla appears in glass of a similar date to that here, and it has been suggested that there the choice derived from Petronilla de Nerford, wife of William de Nerford, lord of the manor of Cley in the thirteenth century. ³