The little board-and-batten church of St Stephen's, Tuahiwi (1867), is [the oldest surviving] Maori Mission church in the South Island.

The first mission to convert South Island Maori to Christianity was established by the Weslyan church at Otakou in 1840. Three years later Tamihana Te Rauparaha (?-1876) and Henare Matene Te Whiwhi (?-1881) of Ngati Toa travelled around the South Island preaching the Anglican doctrine and, in 1844, Anglican Bishop George Selwyn (1809-1878) first visited the South Island. In 1859 the diocese of Christchurch established a Maori Mission, headed by Reverend James West Stack (1835-1919), a fluent Maori speaker. Stack had previously worked for the Church Missionary Society in the North Island and became a noted expert and author on Maori matters. It was decided to base the mission just outside Kaiapoi, which had traditionally been the site of the major Ngai Tahu pa, but which was now being settled by Pakeha. Local Maori gifted 20 acres (8 hectares) of their reserve land at Tuahiwi to the Mission, and Stack erected a four-roomed cottage, a school, and finally a church on this land. [In the meantime, Stack opened the newly built Māori church at Arowhenua in South Canterbury in 1866]. The Mission made a concerted effort to persuade local Ngai Tahu to move from Kaiapoi to Tuahiwi. Many did move, principally between 1861 and 1865. Government subdivision of the Kaiapoi Reserve, which transferred the ownership of the land from a collective title to many individual ones, was undertaken, in part, as a way of further encouraging the shift from Kaiapoi. As a result a settlement sprung up at Tuahiwi, under the auspices of the Anglican Church.

The foundation stone of St Stephen's was laid by Sir George Grey, Governor of New Zealand, on 9 February 1867 and the church was completed later that year. Local Maori took the opportunity at the laying of the foundation stone to express their concerns over the land sales to the Crown. They also requested the return of a portion of the burial ground at Kaiapoi, which Grey granted. The government donated £200 towards the cost of the church; the remainder was collected from surrounding districts by two prominent church wardens, Pita Te Hori and Koro Mautai.

The exterior cladding of St Stephen's is vertical board-and-batten, and it was originally roofed in shingles. It is thought to have been designed by Reverend A.G. Purchas (1821-1906), who, although untrained as an architect, had worked with Frederick Thatcher in Auckland and was responsible for a number of churches in the Auckland district. Thatcher had designed many of the Selwyn Gothic churches, noted for their exterior framing, steeply pitched gable roofs and small diamond-glazed windows and so-called after George Selwyn, Bishop of New Zealand from 1841 to 1867. Purchas first became associated with Thatcher with the building of St Peter's at Onehunga (1848). As its vicar Purchas is believed to have been closely involved with the design of St Peter's, and to have supervised its construction. Purchas then went on to design St James, Mangere (1857), St Bride's, Mauku (1860) and St Peter's at Akaroa (1860-1861).

It appears that St Stephen's was his last design and it is similar in many respects to both St Bride's and St Peter's. Like St Bride's, St Stephen's is interesting because the cruciform plan of both churches is achieved by placing a combined entry porch and bell tower on one side of the nave, with a vestry opposite, rather than constructing transepts. This plan is said by architect Peter Sheppard to have worked particularly well for the small church of St Bride's and certainly Purchas thought so, repeating it at St Stephen's. The symmetry of the design was lost at St Stephen's when the vestry was removed in 1946. The square, three-tiered tower is also characteristic of Purchas's work and this, happily, survives, although the top section was replaced in 1962.

In 1870 the mission house and school burnt down, and Stack and his family moved first to Kaiapoi, and then Christchurch. The Maori mission suffered during the 1870s with the rise of the prophet Hipa Te Maiharoa, whose attempts to protect Ngai Tahu land at Omarama struck a chord with many Maori also concerned over the loss of their land. Stack remained involved with the Maori mission until 1887. After Stack resigned however, historian W.P. Morrell argues, Anglican church involvement with Maori in Canterbury 'languished'. Although there was some revival during the late 1890s, the Church Missionary Society withdrew from their New Zealand mission in 1903, leaving the Maori mission in the hands of the Anglican Church of New Zealand. In the 1920s St Stephen's was attached to Rangiora, and then in the 1940s it became part of the Woodend Parochial District. It still serves as a church today.

St Stephen's is a simple colonial timber church, notable for its balanced proportions and plan, all of which are characteristic of its designer, Purchas. Art historian Jonathon Mane-Wheoki has said of St Stephen's that 'it is one of the most perfectly preserved of a group of later Selwyn Gothic churches....[whose] architectural qualities are of national significance.' St Stephen's is of particular significance as the oldest [surviving] Maori church in the South Island and is directly related to the establishment of the Anglican Maori mission in Te Wai Pounamu. Stack's association with the church is also important; he was the major force behind the Anglican Maori mission, wrote widely about Maori lore, was consulted by the Canterbury Museum and assisted in the preservation of Maori place names. St Stephen's is highly significant to the local runanga, Te Ngai Tuahuriri, whose kaumatua played a major role in the church's foundation.