Rosemary, Lady Firth (1912 – 8 July 2001) was a British social anthropologist, and wife of Sir Raymond Firth. She specialised in the field of domestic economy.
Rosemary Firth (née Upcott) was born in 1912 in London. Her father, Sir Gilbert Charles Upcott, was a distinguished official in the Treasury, holding the position of Comptroller and Auditor General from 1931 to 1946. Firth took a Political Economy degree (MA) in Edinburgh in 1935, and then moved to London. She married Raymond Firth in 1936, and accompanied him to Kelantan in Malaya to undertake fieldwork from 1939 to 1940; Rosemary focused on the domestic economy of the female villagers. On their return to the UK from Malaya in November 1940 the Firths were aboard the RMS Rangitiki, part of Convoy HX 84, when it was attacked by the Germans. From 1940 to 1946 Firth researched supply and demand for the Board of Trade; she wrote up her Malayan research at the same time and published it in 1943 as Housekeeping among Malay Peasants.
The Firths' only child, Hugh, was born in 1946. Following this, Rosemary did not undertake paid employment again until 1961. She took a course in Social Administration at LSE starting in October 1959, followed by various social work placements away from home. On completion in 1961 she started teaching health education at Battersea College. In 1963 the Firths revisited Kelantan in Malaya to observe changes in the 24 years since their last fieldwork. In 1966 she became lecturer in health education at the University of London Institute of Education for many years, whilst continuing her anthropological research interests. She retired in 1978.
When her husband was knighted in 1973, Rosemary took the title Lady Firth. She died on 8 July 2001. Following her death, Sir Raymond established The Rosemary and Raymond Firth Award in the Department of Anthropology at the London School of Economics. This award has the specific aim of promoting Rosemary's interest in 'the anthropology of household management and the organisation of domestic affairs'.
Following her death and that of Sir Raymond in February 2002, the Firths' ashes were interred on 7 June 2002 at the parish church of Thorncombe, West Dorset, where the Firths had had a cottage (Holway Cottage) since 1937.
The Firth anthropological research papers were deposited at the London School of Economics. A note from Rosemary directed their son Hugh to a store of more personal papers, which revealed that Rosemary had been in a secretive later-life affair with her first love, anthropologist Edmund Leach, whom she had first met when she was 16. The letters and papers were published in a 2023 book, Love, Loyalty and Deceit: Rosemary Firth, a Life in the Shadow of Two Eminent Men, co-authored by Hugh Firth and Loulou Brown, Edmund Leach's daughter.