The church stands in the centre of the former village of Little Woolstone, on the W side of Milton Keynes. It consists of a chancel with a N vestry, and a nave with a S porch and a weatherboarded bell-cote at the W end. Construction is of limestone rubble with yellow stone dressings and red tiled roofs. The late-12thc font is older than any of the present fabric, so far as can be seen. The nave was rebuilt in the 14thc, the porch added in the 16thc and the chancel was rebuilt in the 19thc (although the chancel arch is 13thc). There is evidence for a projected N transept that was not completed.

Only the chancel and its N vestry are now given over to liturgical use. The nave, separated from it by lockable doors, is now the Woolstones Community Centre. It should be noted that a second church of Holy Trinity, Woolstone (formerly Great Woolstone), built in 1839, is less than half a mile away (SP 875 386). This has also been removed from parish use and is now the Rosebery Music Room.

The Domesday Survey records two holdings in Little Woolstone. Ralph held a manor of 3½ hides from Walter Giffard, held by a thegn of Edward the Confessor called Edward in 1066. A second manor was held by William fitzAnsculf, assessed at 1½ hides, held by King Edward's thegn Ulf in 1066. The overlordship of the main manor passed with the Honour of Giffard to the Clares, Marshals and Valences to the Talbots. In 1630 the heirs of William de Valence were said to be the overlords. The tenancy passed from Ralph to Hugh de Chislehampton by the early-13thc. The Chiclehamptons passed their rights to the Coudrays by 1262, and the Coudrays continued to hold the tenancy until the male line ended in the early part of the 14thc.

Parallels for the font have not been discovered in this county, although there are several examples across the border in Northamptonshire with intersecting arcading. The closest is perhaps at Hinton-in-the-Hedges: a more elaborate affair with foliage ornament but also a band of intersecting arches and a rim carved with dogtooth.