Domnall I “the Freckled” (Scottish Gaelic: Domnall Brecc mac Echdach; English: Donald) (d. 642 in Strathcarron) was king of Dál Riata from about 629 until 642. He was the son of Eochaid I and father of Domangart II.

Domnall suffered four defeats after he broke Dál Riata's alliance with the Uí Néill clan of Irish High Kings. In Ireland, Domnall was defeated by the Uí Néill at the Battle of Mag Rath in 637. He lost to the Picts in 635 and 638 and finally, and fatally, to the Britons of Strathclyde at Strathcarron in 642, where he died. He was succeeded by Ferchar I.