The National Union of Congolese Workers (UNTC), (previously known as the Union Nationale des Travailleurs du Zaire (UNTZa)) is the largest trade union centre in the Democratic Republic of the Congo.

Founded in 1967, the UNTZa was the sole trade union centre in Zaire. In 1997 the union was renamed the UNTC, reflecting the renaming of Zaire to the Democratic Republic of the Congo.