The O'Boyle (Irish: Ó Baoighill) family of County Donegal were a clan of the Northern Uí Néill, a great tribal dynasty of the North Gaels descended from Niall of the Nine Hostages.
The O'Boyles were one of the principal families of the Cenél Conaill within the Northern Uí Néill and originally Chiefs of the Three Tuaths in the northwest of Tír Chonaill (County Donegal).
When these lands passed to The MacSweeneys (Mac Suibhne), the O'Boyle became chiefs of Tír Ainmhireach, later to be known as Críoch Bhaoigheallach, or O'Boyles country, now the Barony of Boylagh.
[1][2] This timeline traces the O'Boyle clan back to Úgaine Mór.