Eochaid mac Domangairt (died ca. 697) was a king of Dál Riata (modern western Scotland) in about 697. He was a member of the Cenél nGabráin, the son of Domangart mac Domnaill and father of Eochaid mac Echdach; Alpín mac Echdach may also be a son of this Eochaid.
He is named in Dál Riata king-lists, the Duan Albanach and the Synchronisms of Flann Mainistrech. In some sources he is called Eochaid Crook-Nose (Riannamail), but modern readings take this is a being a garbled reference to Fiannamail ua Dúnchado rather than an epithet.
The killing of Eochu nepos Domnaill, Eochaid grandson of Domnall Brecc, is reported in the Annals of Ulster for 697 (wikipedia)