Ernest Hill qualified as a member of the Royal College of Surgeons (MRCS) of England and a licentiate of the Royal College of Physicians (LRCP) of London in 1892. Three years later, having worked at Middlesex Hospital, he was awarded the Diploma in Public Health by the University of Cambridge. After serving as a civil surgeon during the first part of the Anglo-Boer War (1899-1902) he settled in Durban, Natal, where he was appointed health officer for the colony in September 1901 and a member of the Natal Board of Health in November that year. He retained this post for 10 years, though by 1904 he was resident in Pietermaritzburg. During these years he became a member of the Natal Medical Council and served on the boards of trustees of Grey's Hospital and the Natal Museum.
Hill published a paper on 'Horse sickness in South Africa' in the British Medical Journal (1902). He also wrote an extensive account of the outbreak of bubonic plague in Natal from 4 December 1902 to 15 August 1903, Report of the plague in Natal, 1902-3 (London, 1904), and issued instructions relating to the plague to the colony's medical officers. During 1906 he reported to the government on Ankylostomiasis (hook worm disease), which was associated with high death rates among Indian hospital patients in the colony, and the life history of the worm Ankylostoma duodenale. The next year he and Dr Leonard G. Haydon* contributed an extensive paper on the development of the malaria mosquito, "A contribution to the study of the characteristics of larvae of species of Anophelina in South Africa", to the Annals of the Natal Museum (1907, Vol. 1(2), pp. 111-158).
After retiring as health officer of Natal in 1911, Hill was licensed to practise in the Cape Colony in September 1913 and settled in East London. In 1917, during World War I (1914-1918) he was assistant director of medical services. By 1926 he was medical officer of health at East London, a member of the Council for Public Health of the Union of South Africa, and a member of the Leprosy Board for Amatikulu and Emjanyana.
He should not be confused with another Dr Ernest Hill, who qualified in Scotland in 1899 and practiced at Cathcart (1907) and later at Ceres (1926).