Architect born at Godley, Cheshire. He was articled to F. & G. Holme of Liverpool between 1887 and 1891. In 1891 he became an assistant to the Liverpool firm of Willink & Thicknesse, who certainly influenced his work. He established his own practice in Liverpool in 1898. In partnership with F.B. Hobbs he was a joint winner of the competition for the Mersey Docks and Harbour Board offices in 1900. By 1903 his partners were F.G. Briggs and H.V. Wolstenholme, with whom he designed the Blue Coat School in Wavertree, Liverpool, in an Edwardian Baroque style. In 1907 he was elected a Fellow of the Royal Institute of British Architects (having been an Associate since 1893). He became the principal Merseyside rival of Herbert Rowse in the use of a muted Neoclassicism derived from America and he collaborated with Rowse in the design of India Buildings, Liverpool (completed in 1930). He was responsible for many other university, church and civic buildings in Liverpool, including the large extension and remodelled entrance to the Walker Art Gallery in 1931–33. His masterpiece is the Parliament Building at Stormont Park in Northern Ireland; his knighthood for his services to architecture was announced on the day of its official opening, 16 November 1932.
Bibliography: R.F. Bisson, The Sandon Studios Society and the Arts, Liverpool, 1965, p. 28; T. Cavanagh, Public Sculpture of Liverpool, Liverpool, 1997, pp. xii, xiii, 128–29, 135, 136, 137, 147; A. Felstead et al, Dictionary of British Architects, 1834–1900, London, 1993, vol. 2, pp. 804–05; G. McKintosh, ‘Thornely, Sir Arnold (1870–1953)’, Oxford Dictionary of National Biography (online edn.), 2011; E. Morris and E. Roberts, Public Sculpture of Cheshire and Merseyside, Liverpool, 2012, pp. xvii, xxv, 29, 218, 221, 222; R. Pollard and N. Pevsner, Lancashire: Liverpool and the South West (The Buildings of England), New Haven and London, 2006, pp. 94–98, 153, 299, 341, 364, 571; J. Sharples, Liverpool (Pevsner Architectural Guides), New Haven and London, 2004, pp. 31, 63-64, 170, 218, 227; The Times, 3 October 1953, p. 8 (obituary).
Emma Roberts, 2012; revised, Terry Cavanagh, September 2025