St James's has a four-bay aisled nave with a clerestorey of tiny quatrefoil windows and arcades with pointed, chamfered arches, octagonal piers and moulded capitals of c.1450. Unusually the S nave doorway is at the W end of the S aisle, under a W-facing porch. The chancel arch is on corbels, and these appear to be contemporary with the arcades, but the label may be a reused 12thc. piece (see VIII Comments/Opinions). The chancel has a N chapel, now a vestry, but the glazed arch to it from the chancel is modern, as is the vestry door itself. At the W end is a short 13thc. tower with a slate-tiled broach spire. Construction is of grey stone rubble with a band of ironstone in the tower. The font is Romanesque.

The major landowner in 1086 was Earl Aubrey, who held 2 hides in Syresham. A church and a priest were noted, but it is unclear whether they were in Syresham, Halse or Brackley, also held by the earl. Osmund held one-third of Earl Aubrey's holding in Syresham. In addition to these holdings, half a hide was held by Ralph of Count of Mortain, and half a hide by Geoffrey from Giles, the brother of Ansculf. Earl Aubrey also held lands in Halse and Brackley, and RCHME suggests that the church at Syresham may have been an offshoot of Brackley. It existed by 1143, when it was part of the earl of Leicester's foundation gift to Delapre Abbey (Leics).

Benefice of Helmdon with Stuchbury and Radstone, and Syresham with Whitfield, Lois Weedon with Weston and Plumpton and Wappenham.

Pevsner dated the chancel arch to c.1200 in its entirety, and considered the corbels 'Late Norman'. The present author would date the corbels with the nave arcade capitals, i.e. 15thc. It is suggested that the outer arch and label date from c.1200, and the hollow-chamfered inner arch on corbels was inserted c.1450.