This volume presents the first critical edition of Catherine of Siena’s Dialogue of Divine Providence (1377–1378), established on the basis of the entire manuscript tradition. The study is accompanied by a historical-literary introduction and a textual note, in which two stemmata (Books I–III and IV–V) are set out. The edition is followed by a detailed discussion of the sources, an appendix of lectiones singulares, and a glossary.