Not much is known of his early training or career, but by 1823 Robertson had established himself in Elgin, Morayshire, Scotland. He worked in both the Greek and Gothic Revival Styles. In addition to numerous public buildings, chapels, churches, mausolea and manses, amongst his domestic architecture he altered and built many country houses. Aberlour House, Banffshire, built in 1838 for Alexander Grant, is perhaps his most noted of the latter.
Robertson died on 12 June 1841 at Elgin. He is commemorated by a tombstone in the Cathedral churchyard.
Colvin, Howard, A Biographical Dictionary of British Architects 1600-1840, 3rd edition (New Haven and London: Yale University Press, 1995), pp. 824-826.
Dictionary of Scottish Architects, 'William Robertson', DSA Architect Biography Report [accessed 02 May 2008]