Donnchadh Ó Dubhda (fl.
1213) was King of Ui Fiachrach Muaidhe.
Donnchadh is almost wholly known from Araile do fhlathaibh Ua nDubhda, which says of him: Dubhaltach Mac Fhirbhisigh gives what appears to be his genealogy (265.2, pp.
598–99, volume I): At 265.5 (pp.
600–601), Mac Fhirbhisigh gives the genealogy of another Donnchadh Mór, son of Taichleach O Dubhda, as having three sons; Donnchach Og, royal candidate of Ui Fhiachrach, Conchabhar, and Uilliam, bishop of Ceall Aladh (Kilalla), stating that the daughter of O Floinn was mother of those sons of Donnchadh Mor.