The Dutch Catholic Union of Building Workers (nl|Nederlandse Katholieke Bond van Werknemers in de Bouwnijverheid), known as "Sint Joseph", was a trade union representing construction workers in the Netherlands.
The union was founded in 1917, and in 1925 it was a founding affiliate of the Roman Catholic Workers' Federation.[1] By 1964, it was the largest affiliate of the Dutch Catholic Trade Union Federation, with 74,348 members.[2] In 1971, it merged with the smaller Dutch Roman Catholic Union of Woodworkers, Furniture Makers, Wallpaperers, and Related Trades, to form the Dutch Catholic Union of the Building and Wood Industries.