Ó Mathghamhna is an Irish surname that translates to "descendant of Mathghamhain," with Mathghamhain meaning "bear" in Old Irish. This surname is primarily associated with the Gaelic culture of Ireland and is often linked to the ancient clans of the region. The Ó Mathghamhna family is historically connected to the province of Connacht, particularly in County Galway. Members of this clan have played various roles in Irish history, including involvement in local governance and military affairs. The name is also sometimes anglicized as "Mannion."