St John's RC Church, Rathfriland Road, Hilltown, Co Down, BT34 5TA

St John's Roman Catholic Church is a small early 19th-century building located on the west side of Rathfriland Road in Hilltown, Co Down, within a graveyard setting. Dating to the 1820s, it displays an unusual T-plan form with the head of the T aligned north-south and facing east towards the road.

The church is roofed in pitched natural slate laid in diminishing courses, with three raised gables to the north, south, and west, each finished with concrete copings, moulded kneelers, and cross finials. A two-stage advanced render eaves course supports half-round metal rainwater goods. The external walls are cement wet dashed and painted, with a smooth chamfered and painted base course and stepped random-width stucco V-jointed quoins.

The principal east elevation is four windows wide, all featuring stained glass in round-headed forms with irregular quoined architraves and Gothic hood moulds that break through the lowest stage of the eaves course. The north and south gables of the main block are blank but crossed by a broad platband at eaves level. Each gable is abutted by an identical gabled porch with pitched natural slate roof, raised concrete-coped gable, and kneelers. The porches have pairs of modern varnished four-panel doors on their east cheeks, set on granite steps, with single windows as those of the church but without architraves and with concrete cills. The west cheeks of the porches are blank.

The rear west elevation of the main block has single windows at either end. Two small lean-to structures flank where the return (the tail of the T) meets the main block. The southern lean-to is a modern boiler house with mono-pitched natural slate roof and louvered doors. The northern structure serves as the sacristy, built in the post-war period with similar construction, a stained glass window to its north face, and a small dashed chimney. The return to the west has single windows to the centres of its north and south elevations and an identical west gable with a projecting porch featuring four-panel doors on each cheek and a plain single window on its gable.

The church's most unusual architectural feature is a single cast-iron post supporting the crossing over the altar.

The setting comprises graveyards to front and rear. The front yard is enclosed by a rubble stone wall with roughly dressed embattled granite copings and a pair of plain wrought-iron gates. Two paths lead to the gable end porches. The graveyard contains an assortment of memorials dating from the 1820s–1830s, predominantly in granite or slate. Some memorials to the rear have been relocated to the west and north boundaries.

The building is shown as a T-plan structure on the 1833 Ordnance Survey 6-inch map. The church has undergone substantial alterations, particularly to fenestration and door elements.