Decretum may refer to:Decretum Gratiani, a collection of Roman Catholic canon law compiled in the 12th century by a jurist named Gratian Decretum Gelasianum, an ecclesiastical text traditionally attributed to Pope Gelasius I, which contains a list of works adjudged apocryphal Decretum de Iudaeis, a series of draft documents of the Second Vatican Council, ultimately released as Nostra aetate Decretum of Burchard of Worms, a collection of canon law compiled in the early 11th century