The Collectiones canonum Dionysianae (Latin for Dionysian collections of canons), also known as Collectio Dionysiana or Dionysiana Collectio ("Dionysian Collection"), are the several collections of ancient canons prepared by a Scythian monk, Dionysius 'the humble' (exiguus). They include the Collectio conciliorum Dionysiana I, the Collectio conciliorum Dionysiana II, and the Collectio decretalium Dionysiana. They are of the utmost importance for the development of the canon law tradition in the West.
Towards 500 a Scythian monk, known as Dionysius Exiguus, who had come to Rome after the death of Pope Gelasius (496), and who was well skilled in both Latin and Greek, undertook to bring out a more exact translation of the canons of the Greek church councils. In a second effort, he collected papal decretals from Siricius (384-89) to Anastasius II (496-98) included (, anterior therefore, to Pope Symmachus (498-514)). By order of Pope Hormisdas (514-23), Dionysius made a third collection, in which he included the original text of all the canons of the Greek councils, together with a Latin version of the same; but the preface alone has survived. Finally, he combined the first and second in one collection, which thus united the canons of the councils and the papal decretals; it is in this shape that the work of Dionysius has reached us.