Domangart Réti was king of Dál Riata in the early 6th century, following his father's death, Fergus Mór.
He had at least two sons: Comgall and Gabrán, both of whom became kings in succession.
The Tripartite Life of St. Patrick states that he was present at the saint's death, c. 493.
His byname, Réti, appears in Adomnán's Life of Saint Columba, in the form Corcu Réti, perhaps a synonym for Dál Riata.
Corcu, a Primitive Irish language term for a kin group, usually combined with the name of a divine or mythical ancestor, is similar to the term Dál.