The Irish surname O’Malley is of patronymic origin being derived from the pre 10th century Gaelic O' Maoileoin, meaning "a descendant of a follower of St John", and was originally recorded only in the province of Connacht in the west of Ireland, particularly in county Mayo. The original territory of the clan were the County Mayo baronies of Burrishoole and Murrisk. The most famous bearer of the name was Grace O’Malley, or Granuaile, who was the 16th Century chieftain of the O’Malley clan and noted sea pirate. Under her leadership the O’Malley’s controlled the atlantic coast of Ireland for most of the 16th Century. Today there are more than 17,000 bearers of the surname O'Malley living in The United States.