Clementina Black, the daughter of David Black, a solicitor and Maria Patten, a successful portrait painter, was born in Brighton on 27th 1854. David Black was Brighton's Town Clerk but when Clementina was a child he became very ill and lost the use of both his legs. Educated at home, mainly by her mother, she became fluent in French and German.
In 1875 Clementina's mother died from a rupture caused by lifting her invalid husband. Clementina, the eldest daughter, was left in charge of an invalid father and seven brothers and sisters. In her spare time Clementina began writing fiction and in 1877, her first novel, A Sussex Idyll was published. After the death of her father she moved to London where she continued her career as a writer.
In 1886 Clementina became friends with Eleanor Marx, the daughter of the political philosopher, Karl Marx. As a result of their friendship Clementina became a member of the Women's Trade Union Association (WTUA). In 1886 Clementina Black was appointed honorary secretary of the organisation. For the next few years she travelled the country making speeches trying to persuade women to join trade unions. In 1888 she attended the Trade Union Congress where she moved a motion on equal pay for equal work.
Clementina Black was also involved in the formation of the Consumers' League, an organisation that tried to cajole customers to put pressure on employers who paid very low wages to women. One successful campaign involved the boycott of Bryant & May matches. This eventually led to the match-girl strike led by Annie Besant in 1888.
In 1889 Clementina Black helped form the Women's Trade Union Association (WTUA). Five years later this organisation joined forces with the Women's Industrial Council. Clementina became president of the council and for the next twenty years she was involved in collecting and publicizing information on women's work.
Her biographer, Janet E. Grenier, has pointed out: "The failure of the WTUA in 1894 led to the formation of the Women's Industrial Council (WIC), a new kind of organization which sent out its mainly middle-class women investigators to see for themselves conditions of working women, after which they wrote reports in an attempt to influence public opinion and government policy. Clementina Black became editor of its journal, the Women's Industrial News, in 1895 and later president of the WIC. She became increasingly active as a speaker and writer on problems facing women workers. She saw low pay as the root of the problem, and from 1896 began to campaign for a legal minimum wage. She was concerned with the plight of women home workers (usually widows or wives of casual labourers), especially in the tailoring trade in east and south London." Black's solution to the problem of low pay was the establishment of wages boards that would enforce a minimum wage for certain types of unskilled workers. She wrote several books on the subject including Sweated Industry and the Minimum Wage (1907) and A Case for Trade Boards (1909).
Clementina Black was an active member of the Fabian Society. In 1906 Clementina Black was appointed as honorary secretary to the Women's Franchise Declaration Committee and was responsible for organising the petition demanding the vote that was signed by 257,000 women. In 1911 she became vice-president of the National Union of Suffrage Societies. She also held a similar role in London Society for Women's Suffrage. From 1912 to 1913 she was acting editor of The Common Cause. Janet E. Grenier has argued: "She realized that, without the vote, women had no power to legislate against poor working and social conditions. She became one of the vice-presidents of the London Society for Women's Suffrage in 1913."
By 1914 the Women's Industrial Council had investigated one hundred and seventeen trades. In 1915 Black and her fellow investigators published their book Married Women's Work. Black was also a member of the executive committee of the Anti-Sweating League and in the years preceding the start of the First World War she was involved with people such as Cicely Corbett Fisher and Hilda Martindale in organizing conferences on the subject. The organisation defined sweated labour as "(1) working long hours, (2) for low wages, (3) under insanitary conditions".
Despite her involvement in political issues, Clementina still found time to write novels until her failing eyesight made it impossible. One of the most successful of her books was The Agitator, a novel based on her experiences as a trade union leader.
Clementina Black died at her home in Brighton on 19 December 1922.