Aillil mac Dúngaile Eilni (died 690) was a Dál nAraidi king of the Cruthin in Ulaid, an over-kingdom in medieval Ireland.
He was the son of Dúngal Eilni mac Scandail (died 681), a previous king.
In the 6th and 7th centuries, the Dál nAraidi were part of a confederation of Cruthin tribes in Ulaid and were the dominant dynasty.
Ailill belonged to a branch of this family settled in Eilne, a plain between the Bann and Bush rivers in modern-day County Antrim, Northern Ireland.
[3] His brother Cú Chuarán mac Dúngail Eilni (died 708) was also king of Dál nAraidi as well as of Ulaid as was his son Cathussach mac Ailello (died 749).