Charlotte Despard had a long and varied career in public life. In 1870, Charlotte French married Maximilian Carden Despard, an Anglo-Irish businessman who had worked in the Far East. Despard travelled with her husband to India and other Asian countries and wrote novels until his death in 1890.

Despard was very religious, and turned from her converted Roman Catholic background to Theosophy in 1899. She became a vegetarian and was Vice-President of the London Vegetarian Society in 1931. She was a member of the Executive Board of the World Congress of Faiths in the 1930s.

Despard became a Poor Law Guardian in Lambeth, London, in 1894. She was known to wear simple black clothing and sandals. She was a leading member of the suffragette movement in Britain, as a member of the Women's Social and Political Union (WSPU). In 1907, the suffragette movement split over methodology and Despard then presided over the Women's Freedom League. She was heavily involved in the Women's Tax Resistance League. Sophia Duleep Singh was also a prominent female tax resister. In 1909 Despard met Mohandas Gandhi in London in relation to her work with the WFL. 

In 1918, Despard stood unsuccessfully as a Labour candidate when women over 30 were given the vote. Despard had shown her sympathies for the Irish Home Rule League, and despite her socialist-pacifist leanings, became involved with Sinn Fein. Her involvement with Sinn Fein was a blow to her brother, John French, Lord Lieutenant of Ireland. In 1921, Despard moved to Ireland and shared a house with Maud Gonne. She continued to travel to London and Europe, but died in Ireland in 1939.