William James Kemp [also known as William James Kemp, Snr.] was born in St. Pancras, London, England in c.1853 and was articled to William Teulon (1823-1900) from 1869 to c.1875. He then worked as an assistant to David Brandon (1813-1897), Daniel Cubitt Nicholls, George Lethbridge (1847?-1924), and to Henry Jarvis (?-1910). He was clerk of works to John Thomas Christopher (1829?-1910) in 1877.
Kemp began practising as an architect in Willesden Green, Middlesex [now London] in 1888 whilst continuing to work as a clerk to Christopher. In 1900 he took over Christopher's practice and from 1905 was in partnership with his son, William James Kemp Jnr. (1882-?) and William Murthwaite How (1873-1957) as Kemp & How.
Kemp senior was admitted a Fellow of the Royal Institute of British Architects (FRIBA) in 1906. His address was given as 6 Bloomsbury Square, London in 1910; Fairlawn, Sutton Road, Muswell Hill, London in 1914; and 4, Bloomsbury Square, London in 1914 and 1926
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