Stewkley is in the E of the county, in the ancient hundred of Mursley. It is a substantial settlement extending for 1½ miles along the road from Buckingham to Leighton Buzzard and Dunstable, 10 miles SE of Buckingham and 3 miles from the Bedfordshire border. The suffix “ley” in its name suggests a woodland settlement and the presence of a North End and a South End are typical indications of the original extent of the clearing, but there is little continuous woodland surviving now, and the landscape round the village has the low rolling character of the Vale of Aylesbury. The church is alongside the main road in the centre of the village, and is an important example of a complete Romanesque parish church with a central tower and lavish sculptural decoration.
It consists of a nave, central tower and chancel with no aisles and no external signs of there having been transepts. The tower has a N stair at the E end of the N wall, slightly projecting from the wall face. The stair rises to within 2 metres of the top of the tall lower stage of the tower, and above it are traces of a blocked arch in the masonry. The tower has round-headed lower windows to N and S, and the bell-storey is decorated with intersecting blind arcading enclosing a single round-headed bell-opening in the centre of each face. The tower masonry consists of irregular small pieces of limestone rubble including some local iron limestone, with some attempt at coursing. The upper part of the tower, including a plain parapet, has been rebuilt in ashlar blocks with gargoyles. When it was seen by the RCHM in 1913, the church was coated in Roman cement except for the E wall of the chancel and the W façade. The windows and blind arcading have chevron decoration, and there are chevron stringcourses at the level of the lower window sills.
The nave has 12thc N, S and W doorways and an elaborate W facade with blind arches alongside the W doorway. The nave windows are decorated with chevron, and there is a chevron stringcourse at sill level and a carved corbel table on the N and S sides. The S porch is 19thc, in a neo-Romanesque style. The chancel is square ended with 12thc lateral windows decorated with chevron and an E window flanked by blind arches, also chevron decorated. It has the usual sill-level stringcourse and lateral corbel tables like the nave. The E angles of the chancel have 19thc angle buttresses with neo-Romanesque chevron decoration. The S chancel doorway now gives access to a free-standing vestry built in 1910. Inside the church, carved decoration is found on the two tower arches, the internal faces of the windows and the ribs and supports of the vaulted square chancel. The church also contains a plain 12thc tub font. The church was reseated and a W gallery added by J. Ball of Aylesbury in 1831-35. In 1844 the chancel vaulting was rebuilt, with the exception of the ribs. It was repaired and again reseated byG. E. Streetin 1862-63. Repairs to the exterior plasterwork were carried out by C. M. O. Scott of London in 1937-38, and further repairs to the fabric were carried out by D. W. Harrington (1961-68) and T. Rayson of Oxford (1974-75).