Zwentibold (or Zventibold, Swentiboldo, 1 January 870 – 13 August 900) is the illegitimate son of the Carolingian Emperor Arnulf of Carinthia.

In 895, his father, then king of East Francia, grants him the Kingdom of Lotharingia, which he rules until his death.

After his death, he is declared a saint and martyr by the Catholic Church.