George William King was born in Hampstead, London, England on 1 November 1863 and was articled to Taylor & Locke in London from 1879 to 1881. The following year he emigrated to Canada. He worked as an assistant to Darling & Curry in Toronto, Ontario in 1882-83 and to Power & Son in Kingston, Ontario from 1884 to 1886. He then returned to Toronto to work in the office of Edward James Lennox (1855-1933). From 1888 to 1890 he was in partnership with George Wallace Gouinlock (1861-1932) in Toronto and then with Arthur Richard Denison (1857-1923) in Toronto in 1890-91. Following the dissolution of his partnership with Denison, King worked alone in Toronto until 1899 when he returned to England.
From 1899 to 1906 King was employed as Assistant Architect and Surveyor by the Brewing firm Whitbread & Co. in London. He then established a private practice in Putney, London which he ran until 1910 when he went back to Toronto. After a decade in Toronto he moved to the Niagara Peninsula in Southern Ontario. From the late 1920s to the early 1940s he worked as a consulting architect.
King was elected a Licentiate of the Royal Institute of British Architects (LRIBA) in 1911. He died in Fort Erie, Ontario on 11 June 1945
Directory of British Architects 1834-1914. Compiled by Antonia Brodie, et al. Volume 1: A-K. London; New York: British Architectural Library, Royal Institute of British Architects/Continuum, 2001