MacDonnell, Macdonnell, or McDonnell is a surname of Irish and Scottish origin.
It is an anglicized form of the Gaelic patronymic Mac Dhòmhnaill, meaning "son of Dòmhnall".
[3] The Gaelic personal name Dòmhnall is a Gaelicised form of the name Donald, which is composed of the elements domno, meaning "world", and val, meaning "might" or "rule".
The name is considered a variation of MacDonald.
MacDonnells are found in both Scottish and Irish nobility, where they have held an important role in the history of both countries.