The Marquess of Donegal is a title in the peerage of the United Kingdom, created in 1791. It is associated with the region of Donegal in Ireland and is part of the Peerage of Ireland. The title has been held by the O'Neill family, who have a long history in Irish nobility. The current holder of the title is the 9th Marquess of Donegal, who succeeded in 2021. The marquessate is known for its historical significance and connection to the Irish nobility, as well as its role in the social and political landscape of Ireland over the centuries.