Bishop Viard died on 2 June 1872. To succeed him a Marist priest, Francis Redwood, was consecrated in London in March 1874, and arrived in New Zealand in November of that year. By papal brief of 13 May 1887 the see of Wellington was erected into an archdiocese, and Bishop Redwood was elevated to the office of Archbishop and Metropolitan of New Zealand.

In 1889 the first Marist House of Studies was founded in Wellington under Father J. B. Pestre, S.M. This seminary was in 1890 shifted to Meeanee where the first ordinations to the priesthood took place in 1893. The seminary was changed to Green-meadows in 1911, where besides providing priests for the Society of Mary in New Zealand, it also sends missionaries each year to work in the Marist Vicariates of Oceania.

With the separation of the ecclesiastical province of New Zealand from Australia, it became necessary for a provincial council to be held, and Archbishop Redwood convened the First Provincial Council at Wellington in 1899. Among other decisions taken was the setting up of a National Seminary for Diocesan Clergy. The founding of the Seminary of Holy Cross at Mosgiel in the diocese of Dunedin was undertaken by Bishop Verdon, of Dunedin. In 1913 Archbishop Redwood asked for and received Thomas O'Shea, S.M., as his coadjutor. Consecrated in 1913, Archbishop O'Shea succeeded to the see of Wellington on 3 January 1935, following on the death of Archbishop Redwood on that date.

In 1940, on the occasion of the Dominion Centenary, Archbishop O'Shea organised the First National Eucharistic Congress which but for the war would have been presided over by Cardinal Hinsley, of Westminister, as Cardinal Legate.

St. Columban's Seminary, Lower Hutt, was opened in May 1943 to train young men from New Zealand for the foreign missions. St. Columban's Mission Society has three mission districts in China (closed at present), four districts in the Philippines, two in Korea, four in Japan, one in Burma, and has charge of parishes in Fiji, Chile, and Peru.

In 1947 Peter McKeefry was appointed coadjutor of Wellington, being consecrated at Auckland by Cardinal Gilroy, of Sydney, and on the death of Archbishop O'Shea, on 9 May 1954, he succeeded to the see of Wellington.

On 23 May 1962 Owen Noel Snedden was appointed titular Bishop of Acheloo and Auxiliary Bishop of Wellington, and was consecrated 22 August 1962.