Born in London, Ethel Sargant was the third daughter of Henry Sargant and Emma Beale. She attended the North London Collegiate School, then studied Natural Sciences at Girton College from 1881 to 1885. She undertook botanical work at home from 1885 to 1892, then worked in the Jodrell Laboratory at Kew Gardens, under Dr D H Scott, from 1892-93. She then worked at seedling anatomy in the 'Jodrell Junior' Laboratory, which she set up in her mother's garden at Quarry Hill, Reigate. She published in the Annals of Botany from 1893 onwards. She became a Fellow of the Linnean Society in 1904 and was the first woman Member of the Council of the Linnaean Society from 1906-10. She gave a course of advanced lectures in Botany for London University in 1907. Ethel Sargant bought the Old Rectory in Girton village and went to live there in around 1912. She was elected an Honorary Fellow of Girton College in 1913. In the same year she was President of Section K (Botany) of the British Association, at its meeting in Birmingham, and was the first woman to hold that office in any section. She was elected President of the Federation of University Women in 1918. She organised a register of University women qualified to do work of national importance 1914-18, which was afterwards taken over by the Ministry of Labour. Ethel Sargant died in Sidmouth in 1918. She bequeathed her botanical library and bookcases to Girton, and the Ethel Sargant Studentship for research in Natural Sciences, especially in Botany, was endowed by friends in her memory in 1919.