St Theresa's RC Church, 145 Melmount Road, Sion Mills, Strabane, Co. Tyrone, BT82 9EX

St Theresa's Roman Catholic Church is a triple-height modernist church built between 1962 and 1966 to designs by architect Patrick Haughey. It stands prominently on the west side of Melmount Road at the north side of Sion Mills village, and is set within the Sion Mills Conservation Area.

The church is rectangular in plan, aligned east-west, with a single-storey side chapel to the north and vestry to the south. It sits on a paved podium to the east and north. The principal structural and visual features are the shallow-pitched copper roof with copper tympanum and fascia, timber-sheeted cantilevered soffits, and a copper-sheeted spire to the west end. A continuous recessed stained glass clerestorey runs beneath the eaves on three sides, its panels divided by steel uprights, with full-height stained glass windows to the west elevation. Gutters and downpipes are concealed behind slate strips. The walling is sand-lime brick over a recessed slate plinth.

The dominant external feature is a substantial slate frieze by renowned Irish sculptor Oisin Kelly, depicting the Last Supper. This frieze is positioned beneath the clerestorey and is flanked by slightly projecting side walls representing columns supporting a pediment. The entrance, set below the frieze, is recessed and consists of a continuous stained glass screen wall with three stained hardwood doors—double doors to the centre, each with vertical glazed strips and bronze pull handles.

The south elevation is blank beneath the clerestorey, divided into brick panels separated by thin recessed slate strips, with a full-height window to the west end. The single-storey vestry to the south has a flat leaded roof and a square-headed hardwood sheeted entrance door with an upper glazed panel flanked by horizontal stained glass windows, all set within a slate panel. The north elevation is similarly detailed to the south but reversed, with the side chapel offset to the right. The side chapel is accessed via a door in a stained glass screen wall, with other elevations blank. The rear elevation is blank.

The site features a tarmac forecourt and carpark to the north, bounded by sand-lime brick walls. Grassed areas and a small grotto lie to the south, with a churchyard bounded by hedging to the north.

The church's windows throughout are hand-crafted leaded stained glass by Dublin artist Patrick Pollen. These include depictions of St Theresa of Lisieux in the clerestorey above the gallery, and at the altar end a chalice and cross worked into the glass. In the porch, the glass depicts Christ's parents: Mary spinning and Joseph at his carpenter's bench.

The interior is spare, with grey brick walls and sheeted ceiling. Light is admitted by the continuous clerestorey and the full-height west windows. A circular font carved by Oisin Kelly sits next to the altar and depicts biblical imagery including the Good Shepherd with his flock, the wise virgins, Noah in his ark, and an angel slaying a winged beast. The altar furniture was designed by Werner Schurmann, and the original sanctuary cross, since replaced with a more traditional one, was the work of Patrick McIlroy. The carved stations are by Ray Carroll.

The church was designed in 1960, before the Vatican II decision to bring the congregation into closer association with the celebration of mass. Consequently, it retains the long, elongated plan reminiscent of the early Christian basilica associated with the former liturgy. The building represents a significant crossroads in Ulster church architecture, claimed as the province's first truly modern church, bearing few restrictions of tradition. It demonstrates the successful integration of modern design with its surroundings, incorporating notable artworks principally from Irish sources. The church has, since its erection, played an important role in the social fabric of Sion Mills and stands as an excellent example of the integration of art into modern ecclesiastical architecture, making a positive contribution to the streetscape.