Nem Moccu Birn was a seventh-century Irish saint who served as the abbot of the monastery on the Aran Islands. Following the death of Enda of Aran, he became one of the earliest recorded successors to lead the monastic community. He belonged to the Dál Birn lineage of Ossory and was considered a relative of Saint Ciarán of Saigir. Historical records indicate that he held authority over the monasteries of the islands during his leadership.