William Mason (24 February 1810 – 22 June 1897) was a New Zealand architect born in Ipswich, England, the son of an architect/builder George Mason and Susan, née Forty. Trained by his father he went to London where he seems to have worked for Thomas Telford (1757–1834). He studied under Peter Nicholson (1765–1844) before eventually working for Edward Blore (1787–1879). In 1831 he married Sarah Nichols, a Berkshire woman apparently fifteen years older than he was. A son was born in the first year of their marriage. In 1836 he returned to Ipswich to practise. Having worked at Lambeth Palace he had attracted the interest of the Bishop of London who now employed him independently designing churches and parsonages. These included three commissions for churches in Essex: St Lawrence, East Donyland; St Botolph, Colchester; and St James, Brightlingsea. The most remarkable of these is St Botolph's (1838) in white brick and Norman style. Apparently Georgian in plan and in its interior it strikes a Medieval note outside. St James (1836), also white brick and in the lancet style and resembling some of Blore's work, is very like St Paul's Church Auckland which Mason built a few years later. Perhaps because of economic hardship, perhaps because of ambition in 1838 the Masons emigrated to New South Wales.
In Sydney Mason worked for the Colonial Architect Mortimer Lewis. He had a success in winning first and second prizes for a new Mechanics' Institute, submitting Gothic and Classical designs, a sign of the rising competition between these styles. He built wheat silos on Cockatoo Island, a task requiring engineering ingenuity. It seems that here he acquired his acquaintance with verandas. A new Government House was then under construction which had been designed by Edward Blore while Mason had still been on his staff in 1835. He may have worked on the drawings.
Perhaps ambition called again. He was offered an appointment as "Superintendent of Works" to the nascent government of William Hobson, Lieutenant Governor designate of New Zealand, which he accepted, sailing to join Hobson at the Bay of Islands where he arrived on 17 March 1840. He thus became the first professionally trained architect in New Zealand. His title was officially "Superintendent of Public Works" but he maintained he had been appointed "Colonial Architect". He adopted that title which was used by government officers in addressing him. He went to assist with establishing the new capital, Auckland, in September 1840. There he oversaw the erection of the prefabricated first Government House before resigning in 1842 and going into partnership with Thomas Paton. Formerly the government postmaster Paton had also resigned and the two men set up as auctioneers and architects. Mason designed the church of St Paul which was started in 1841. He had bought land and now built on it without making a fortune, put up premises for the New Zealand Banking Company and designed houses. He became involved in other commercial affairs but in 1841 his nine-year-old son was drowned in a well. The boy may have been murdered and his parents were deeply distressed.