Fergal mac Máele Dúin (died 11 December 722) was High King of Ireland. Fergal belonged to the Cenél nEógain sept of the northern Uí Néill. He was the son of Máel Dúin mac Máele Fithrich (died 681), a King of Ailech, and great grandson of the high king Áed Uaridnach (died 612). He belonged to the Cenél maic Ercae branch of the Cenél nEógain and was King of Ailech from 700 to 722. Fergal became High King in 710, on the death of Congal Cendmagair of the Cenél Conaill. He ruled from 710 to 722.