15 reactions | Irish last names are instantly recognizable to many, particularly as most begin with an O' or Mc. Even those that don't have either prefix are usually Anglicizations of ones that do in the Irish language ☘☘ If you're wondering where these distinctly Irish prefixes came from, it goes all the way back to Gaelic Ireland. Like many other cultures around the world, the old clans and dynasties of Ireland operated on a system of patronymic last names. | Irish Star US | Facebook