Willy Peirens (born 19 August 1936) is a former Belgian trade union leader.

Born in Deinze, Peirens was active in the Catholic Workers' Youth, becoming its national co-ordinator in 1959. In 1968, he transferred to become youth officer at the Confederation of Christian Trade Unions (ACV), then in the early 1970s became the co-ordinator of its regional structure. In 1977, he became secretary of the ACV's Flemish region, and in 1987, the ACV's national president.^[1] In 1989, he was additionally elected as the president of the World Confederation of Labour. He retired in 1999, but was made honorary president of the ACV.^[2]