The Union of Mineworkers of Belgium (French: Centrale syndicale des travailleurs des mines de Belgique, CSTMB; Dutch: Nationale Centrale der Mijnwerkers van België, NCMB) was a trade union representing coal miners in Belgium.
The union was established on 25 December 1889 as the National Federation of Belgian Miners, incorporating the four major regional unions, which represented Liège, The Center, the Borinage and Charleroi in its early years it focused on reducing working hours and obtaining pensions for elderly miners.
Once these were achieved, it also obtained the provision of washing facilities at mines, and a ban on women or children working underground.
[1] On 1 March 1919, it was reconstituted as the "Union of Mineworkers of Belgium", and its membership increased dramatically, to 123,468 by the end of the year.
Closures continued, and by 1994 the union had fewer than 10,000 members remaining.