The Young Christian Workers (YCW; French: Jeunesse ouvrière chrétienne) is an international youth organization founded by the Catholic priest Joseph Cardijn in Belgium as the Young Trade Unionists. The organization adopted its present name in 1924. Is it regarded as the most influential wing of the Catholic Action movement.
Its French acronym, JOC, gave rise to the then widely used terms Jocism and Jocist. In 1925, the JOC received papal approbation, and in 1926 spread to France and eventually 48 other countries.