William James Kennedy was born in Stewarton, Ayrshire, Scotland in 1877 He was articled to William Hay (1818-1888) and George Henderson (1846-1905) of Hay & Henderson in Edinburgh from 1894 to 1899 and remained with them as their assistant until 1902. He also attended Herriot-Watt College in Edinburgh.
He commenced practice as an architect in Edinburgh in 1902. His practice specialised in the interior design and decoration of country houses. He also lectured on re-resisting construction at Heriot-Watt College in Edinburgh.
Kennedy was admitted a Licentiate of the Royal Institute of British Architects (LRIBA) in 1911 His address was given as 13, South Charlotte Street, Edinburgh in c.1902 and 1912; 9, Pentland Terrace, Edinburgh, Scotland in c.1903; 30, Mayfield Terrace, Edinburgh, Scotland in c.1904; and 30 St. Andrew Square, Edinburgh. 1914 and 1915.
Kennedy is listed in the Kalendar of the Royal Institute of British Architects 1915-16. There were no issues of the Kalender for 1916-17 and 1917-1918. He is not listed in the Kalendar for 1919-20, or later issues. He died in Cupar, Fife, Scotland on 19 November 1949
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