Muiredach of Killala was a 6th-century Irish presbyter and the founding bishop of Killala. Belonging to the Cenél Lóegaire, he was linked to the royal lineage of King Lóegaire mac Néill. Although some traditions associate his leadership of the Killala church with the time of Saint Patrick, historical records suggest he was active later in the century. He is noted for meeting Saint Columba in Ballysadare around the year 575 before eventually retiring to an island.