Clan O'Carroll is a historic Irish clan that originated in the province of Leinster, specifically in County Offaly. The clan's name is derived from the Gaelic "O'Ceatharlach," meaning "descendant of Ceatharlach." They were known for their influence and power in the region during the medieval period, particularly in the 12th century. The O'Carrolls were traditionally associated with the Kingdom of Ely, which played a significant role in Irish history. Over time, the clan faced challenges from other families and external forces, leading to a decline in their power. Today, the O'Carroll name is still recognized, and descendants can be found worldwide.