The Union of Belgian Stoneworkers (Dutch: Centrale der Steenbewerkers van België; French: Centrale des Ouvriers de la Pierre de Belgique, COPB) was a trade union representing quarry workers in Belgium. The union was founded in 1889 as the National Association of Stone and Plaster Workers. It included quarry workers, stonemasons, and paviours, although the quarry workers were always the strongest section, and the stonemasons later left to join the construction workers' union. From 1893, the union published Le Carrier, but until 1906 it achieved little.