The name of the village first appears as Pinnora in 1232. "Ora" means "bank" or "edge" and the church is set on a bank. For most of its history Pinner was not a parish nor did it form part of the diocese of London. Originally it was a chapel subordinate to the ancient church of St Mary, Harrow on the Hill, forming part of the deanery of Croydon which came under the immediate jurisdiction of the Archbishop of Canterbury. This was because the Archbishop was the Lord of the Manor of Harrow. Over the years St. John's grew independent of St. Mary's in many ways, but it was not until 1766 that Pinner became a parish independent of Harrow. The relationship between them is acknowledged by the fact that the Vicar of Harrow is patron of the living of Pinner. In 1836 the two parishes were transferred to the ecclesiastical jurisdiction of the Bishop of London. In recent times, as the population increased, Pinner Parish Church has in turn become the mother church of several new parishes - St. Anselm's, Hatch End to the North; St. George's, Headstone to the East; St. Alban's, North Harrow to the South East and St. Edmund the King, Northwood Hills to the North West.
The village of Pinner was never of any great importance, and no wealthy or influential mediaeval family ever resided in the parish. Consequently the church has no elaborate architectural features, although it was built during the Decorated Period of Gothic architecture. For the same reason it has no examples of the ornate memorials or chantry chapels which are to be found in some churches of this period. It is a very simple village church which has been described by that distinguished architectural historian, Sir Nicholas Pevsner as "one more of the all round typical minor Middlesex churches". Its greatest assets are the overall proportions, the five-bay nave arcades the chancel arches and the tower which dominates the surrounding area.
An archiepiscopal charter of the 14th Century, confirming a grant made a century earlier, indicates that there was a congregation in Pinner by the 1230s, but it is difficult to tell whether any part of the present church fabric dates from that time. What we know is that Archbishop Reynolds authorised the dedication of the existing building in 1321. It follows, therefore, that the main structure must have been built in the early 14th century. The plan was originally of simple cruciform shape, comprising nave, aisles, chancel and transepts only. The tower, south porch and five-light east window were added in the 15th century. The Lady Chapel, which was dedicated by the Bishop of London in 1938, was added in 1859, originally as an aisle to accommodate the scholars of the Royal Commercial Traveller's School, Hatch End, now the Harrow Arts Centre.