Harkstead stands on the N bank of the Stour estuary, 5 miles W of its mouth at Harwich harbour and 6½ miles S of Ipswich. The village stands above Holbrook Bay in mostly arable farmland with some pasture and woodland. The church is 0.4 miles to the E of the village centre with Harkstead Hall Farm to its E. St Mary’s comprises a nave with a S aisle and S porch, chancel with N vestry and W tower. The N wall of the nave is 12thc. with two lancets, refaced on the exterior and a blocked 12thc. doorway. The masonry here is of septaria. Inside, the arch of the easternmost of the 12thc. windows has a 13thc. narrative wall painting. A brown septaria S aisle was added to the 12thc. nave around 1300. The three bay
arcade and cusped Y-tracery aisle windows indicate this period, although the windows themselves were renewed in 1875. The S doorway and its porch are of the same campaign. In the 15thc. the aisle was extended E to form a short chapel alongside the chancel. Here the windows are Perpendicular. The chancel itself was rebuilt in 1867, with a knapped flint facing. It has no chancel arch, although there are coloured marble shafts supporting the westernmost roof truss, and its furnishings are all of the 19thc., although it retains a beautiful 14thc. Easter Sepulchre on the N side. The tower is 15thc. with characteristic W window and bell-openings, and a plinth with tracery and quatrefoil reliefs. It is constructed of a mixture of flints, septaria, ashlar, pebbles and brick or tile, and its brick battlemented parapet may be 18thc. Some idea of the extent to which the church has been restored may be gained from the etching of 1846 by Henry Davy. This shows a view from the SE, and all the visible windows of the S aisle, chapel and chancel lacked tracery, as did the tower bell-openings which had been blocked with brick. The first restoration, in 1867 by W. Slater and R. H. Carpenter of London, involved the rebuilding of the chancel in knapped flint with Ancaster stone dressings in a style of c.1270-1310. The remainder of the church was restored the same firm’s designs in 1875. The 12thc. N windows and doorway and the 13thc. wall paintings were revealed at that time, and tracery was added to the aisle windows. The nave and aisle were re-roofed at this time, the porch restored and the vestry added. The only feature recorded here is the N doorway.