St Mary’s Church at Chilthorne Domer is a small medieval building whose fabric records work from the thirteenth to the fifteenth centuries, with later nineteenth‑century restoration. It is built of Hamstone coursed rubble with ashlar dressings, and the roofs vary between Welsh slate over stone‑slate base courses on the chancel, lead behind parapets on the nave, and stone slabs on the porch. The plan is a two‑cell arrangement of a two‑bay chancel and a three‑bay nave, with a south porch, a north‑east vestry or organ chamber, and a later vestry opposite the porch. The chancel is probably late thirteenth century, although its east wall was rebuilt in the nineteenth century. The east window is a three‑light reticulated design with a plain label, and the north side has a nineteenth‑century two‑light flat‑arched window with cusped lights. Opposite is a fifteenth‑century two‑light window, a simple cusped lancet, and a blocked four‑centred arched doorway. The organ chamber has a three‑light geometric traceried window in its east gable.
The nave shows evidence of an earlier, higher chancel roofline in its east wall. It has a chamfered plinth, a string course with gargoyles, and a low battlemented parapet. The south‑east corner buttress carries two scratch dials. The west end has paired buttresses rising to about two‑thirds height, and the north‑east corner contains a square roof‑stair turret. The north wall has two two‑light reticulated traceried windows with labels, while the south wall has two fifteenth‑century three‑light traceried windows set in hollowed arched recesses. The west wall is plain and shows the line of the pre‑battlemented steeply pitched roof. It is crowned by a small oblong bell turret of the Brympton type, with two four‑centred arched openings to each face above a moulded corbel, and a pyramidal roof with gablets, cross finial and corner pinnacles.
The south porch is probably fourteenth century, with a simple moulded pointed outer arch and an inner arch that may be earlier, with a double‑chamfered order. The door is very early and retains the plate for a sanctuary handle. The porch has a pointed barrel‑vault ceiling under a stone‑slab roof, with a string at the springing level. The vestry opposite the porch is likely twentieth century.
The chancel interior has a nineteenth‑century ribbed and boarded roof, and the east and north walls are probably nineteenth‑century rebuilds. The south‑west window has a cinquefoil cusped rere‑arch. The chancel arch has a double chamfer on corbel heads. The nave roof is a cusped braced queen‑post structure, probably fifteenth or sixteenth century, with moulded timbers, panelling and leaf bosses. The north‑wall windows have simple rere‑arches. The walls are otherwise plain, with a small stoup near the south door.
The fittings include a nineteenth‑century timber reredos with side panels, distinct from the later Pinwill work elsewhere in the region. The pulpit is an early seventeenth‑century octagonal timber piece with panelled sides, a matching back panel and a flat‑topped tester. The pews incorporate seventeenth‑century work in the dado panelling and bench ends, with some original doors reused in the dadoes. The font is an octagonal panelled bowl on a square panelled shaft, fifteenth century, with a seventeenth‑century cover.
In the north wall of the sanctuary is a recumbent effigy in a segmental‑arched recess. The effigy, dated to about 1275, shows a knight in chain mail with hands in prayer, a standard form for the period. A broken bell, probably early, lies at the west end of the church. The churchyard contains later memorials that extend the parish narrative into the modern period, including the graves of Piers Thomas Simon and Lieutenant Richard Wyndham Madden, and the lychgate plaque commemorating Lieutenant Keith Madden, Major David Madden and Lieutenant Richard Madden.
