Yvonne Helene Kapp (née Mayer) (17 April 1903 – 22 June 1999) was a British writer and political activist.
[1] Yvonne Hélène Mayer was born on 17 April 1903 at 170 Tulse Hill, London, into a Jewish immigrant family, daughter of prosperous vanilla merchant Max Alfred Mayer (1871–1948) and his wife Clarisse Fanny Bielefeld (1878–1960).
[2] She started work with a brief stint on the Evening Standard and moved on to the Sunday Times.
Subsequently, she worked for the Medical Research Council, and later as a translator, and writing her magnum opus, a life of Eleanor Marx.
Kapp also co-translated a volume of Bertold Brecht's short stories.