Castlereagh Presbyterian Church, 79 Church Road, Castlereagh, Belfast, County Antrim, BT6 9SA

Castlereagh Presbyterian Church is a symmetrical, double-height building in the Greek Revival style, built between 1834 and 1835 to designs by the architect John Millar, on the site of an earlier church. It stands on the west side of Church Road, Castlereagh, on a mature elevated site overlooking Belfast to the west.

The congregation at Castlereagh has a history stretching back to at least 1652, when it is thought the first minister, the Reverend Hugh Wilson, a native of Scotland, was ordained. Originally a joint charge, with one section worshipping at Knock and the other at Breda, the congregation came together in 1720 to erect a church on the present site, from which time it became known as Castlereagh. An engraved tablet in the porch suggests the 1720 church may have been replaced or remodelled in 1754, though further evidence for this is lacking. All the Presbyterian churches on the County Down side of Belfast are considered daughters of this first church, which was for many years the only Presbyterian church in the district. By 1826 a school house had been built to the north of the church, later converted to a church hall in 1939. The Townland Valuation of 1828 to 1840 records a Presbyterian Meeting House with a return, valued at £9 6s, along with a session house, caretaker's house, and carriage house.

With Belfast's expanding population, the old church became insufficient for the needs of the congregation. Building work on the present church, under the supervision of John Millar, commenced in June 1834 and the building was opened on 16th August 1835. The Belfast Newsletter and the Northern Whig both reported on the opening. The Northern Whig noted: "This house…has been erected at a very heavy expense, by the exertions of the congregation and the friends of their respected Pastor, the Rev. Mr Haslett. The new house has been erected from a design and under the superintendance of our talented young townsman, Mr John Millar, architect, to whom the lovers of classical architecture owe a debt of gratitude. This house does the utmost credit to Mr Millar's talents. Viewed in its design, its altitude, or even its decorations, as a whole, or in part, it pleases the eye and satisfies the taste. It is adorned by a Belfry (the first instance of the kind we know of, on a Presbyterian house of worship, in Ireland), whose picturesque appearance, and commanding situation, render it very conspicuous." The Ordnance Survey Memoirs were rather more critical about the building process: "The parishioners who held seats in the former old meeting house were obliged to raise 300 pounds. There was 1,100 pounds raised by subscription, making the total amount of the cost 1,400 pounds. They employed some country architect to execute the plan and before 6 months it almost fell to the ground. It is now partly refinished. There are 47 seats in the gallery and 68 in the aisle. It is capable of containing 800 persons, there is 700 of a congregation."

The church is a well-preserved example of Millar's ecclesiastical work in his preferred neo-classical style, and a precursor to his distinguished Portaferry Presbyterian Church of 1841. The belfry appears to be the first example of its type on a Presbyterian church in Ireland. Scholars have noted that the idiosyncratic Ionic capitals used by Millar on the portico derive from the interior columns of the Temple of Epicurus at Bassae, and may represent the earliest external use of that order in the British Isles. Millar is believed to have known the details from the plates in the fourth volume of The Antiquities of Athens, published in 1830, of which he owned a copy.

The building has a T-shaped plan, with a taller entrance bay to the east and a two-storey modern extension to the rear. The roof is pitched natural slate with blue and black angled ridge tiles. The walling is painted smooth render with a chamfered base. Cast-iron half-round rainwater goods are fitted throughout. Windows are leaded and stained glass timber casements at ground floor level, with round-headed multi-paned casements to the upper floor.

The principal east-facing elevation features a distyle in antis Ionic portico — the right capital head is a replacement — with antae framed by pilasters, an entablature, and a parapet. Central piers support a square podium with an oculus to each of its four sides, above which rises a circular turret with eight facets divided by pilasters, surmounted by a moulded entablature, a copper cupola, and a ball finial. The cheeks of the antae each have a three-over-three window with side-lights at first-floor level, and modern timber double-leaf doors at ground-floor level. Both the south and north elevations are four windows wide on each floor. The west, or rear, elevation is almost entirely abutted by the modern extension.

The interior is relatively unchanged, retaining a typical Victorian layout including box pews. Griffith's Valuation of 1861 records the church with its return and sexton's house, valuing the buildings at £50 and the graveyard at £2.

A manse was erected and a church bell presented in 1874. During the ministry of the Reverend John Boyd Thomson, from 1877 to 1915, the church was thoroughly renovated. It was renovated again in the 1930s, when a new church room was added to the rear. A pipe organ was installed around 1920 and Mr Robert McDowell presented a clock. During the ministry of the Reverend James Little, from 1915 to 1946, a sexton's house was erected as a First World War memorial, reflected in a rise in the valuation of the church buildings to £58 in 1922. The Reverend James Little was a particularly distinguished minister, serving as Member of Parliament for County Down from 1939 until his death in 1946. A larger church hall was built on a site opposite the church in 1966, with a minor hall added shortly afterwards. In 2001, a three-storey extension housing administrative facilities was added to the rear of the church, replacing the original rear return and a previous extension.

The site is large and attractive, with mature trees and views westward over Belfast. To the south lies a cemetery, accessed through a set of roughcast-rendered Ulster gate piers, containing a variety of tombs and headstones, the earliest of which dates from 1779. The eastern boundary to the road is defined by original gates and railings featuring fluted round piers with a Greek-key frieze, topped by round masonry caps and surmounted by ornate urns. The front of the church is lawned with a central pathway. A tarmacadamed car park and meeting house lie to the north. The original boundary wall, gates, and railings all contribute to the historic integrity of the site. The listing extends to the church, gate pillars, gates, and railings.