Henry Seton Morris was born in Bath, Somerset, on 22 June 1869 and was articled to William James Willcox (1838-1928) in Bath from 1885 to 1890. He then worked as an assistant to Charles John Phipps (1835-1897) from 1890 to 1892; in H.M. Office of Works from 1892 to 1898, and in the War Department from 1898 to 1902. He also attended the Royal Academy Schools in London from 26 January 1892 to January 1897. From 1895 to c.1897 he was in partnership with Mackay Hugh Baillie Scott (1865-1945) as Baillie Scott & Seton Morris at 30 Great James Street, London. They designed a number properties on the Isle of Man . The partnership was short-lived and by 1899, Morris had returned to working in the H.M. Office of Works where he remained as an architectural draughtsman until 1902 when he moved to South Africa.
Following his move to South Africa Morris was employed by the Public Works Department in Transvaal as an assistant architect for six months. He then set up in private practice in Johannesburg. Morris became a member of the Transvaal Institute of Architects in 1903 and a Council member of the Institute in 1904, a position he held until 1907. He also taught architecture at Transvaal University College. By 1909 he had returned to London. In 1909 he passed his qualification exam and later that year was elected an Associate of the Royal Institute of British Architects (ARIBA). Not long after this he went to Burma [now Myanmar] where he worked in the Public Works Department in Rangoon. In 1914 he was elected a Fellow of the Royal Institute of British Architects (FRIBA).
In addition to his work as an architect, he was also an accomplished watercolour painter, although there is no evidence that he exhibited. He died in Rangoon, Burma [now Myanmar] on 18 January 1915.
Directory of British Architects 1834-1914. Compiled by Antonia Brodie, et al. Volume 2: L-Z. London; New York: British Architectural Library, Royal Institute of British Architects/Continuum, 2001
'Obituary'. The Builder vol. 108, 22 January 1915 p. 99
'Obituary'. Royal Institute of British Architects Journal vol. 22, 1915 pp. 191, 280