Ciarán of Saigir, also known as Ciarán mac Luaigne or Saint Kieran, was one of the Twelve Apostles of Ireland and is considered the first saint to have been born in Ireland, although the legend that he preceded Saint Patrick is questionable. Ciarán was bishop of Saighir (Seir-Kieran) and remains the patron saint of its successor, the diocese of Ossory.

The Twelve Apostles of Ireland were twelve early Irish monastic saints of the sixth century who studied under St Finnian at his famous monastic school Clonard Abbey at Cluain-Eraird, now Clonard in County Meath.