Domhnall Ó Madadhan, chief of Síol Anmchadha, fl.
In 1567 he surrendered his Gaelic title and was in return appointed Captain of his Nation by letters patent from Elizabeth I.
Despite most of the family rebelling during the Nine Years' War (Ireland), Domhnall himself did not participate.
During the winter of 1602–03 he attacked the followers of Dónall Cam Ó Súilleabháin Béirre.
By his wife, Morne na Maigh O'Kelly of Creagh Castle (Ballinasloe) he had the following known issue: