Bryan is a surname found in the English-speaking world.
[2] Another origin of the surname is as a patronymic, being borne by someone who was son of an individual named Bryan.
In addition to being found in Brittany, it was used among the Breton followers of the Normans who appear in England and Ireland.
Alternatively, Bryan might be the anglicized form of the Irish surname O'Brien.
[3] The Irish spelling of the surname Brien, Brian or the Norman spelling Bryan would then have a much longer origin in Ireland than in Brittany, predating the Normans.