The Ó Cathail family is an Irish surname that originates from the Gaelic name Ó Cathail, meaning "descendant of Cathal." The family is historically associated with the province of Connacht in Ireland, particularly in County Galway. The name has variations, including O'Cathail and O'Cathal, and is linked to several notable figures in Irish history. Members of the Ó Cathail family have played roles in various aspects of Irish culture, including politics and the arts. The family name is often connected to the ancient Gaelic nobility, and its lineage can be traced back to the Kings of Connacht. Today, the Ó Cathail name continues to be recognized in Ireland and among the Irish diaspora.