Mél of Ardagh, also written Mel or Moel, was a 5th-century saint in Ireland who was a nephew of Saint Patrick. He was the son of Conis and Patrick's sister, Darerca. Saint Darerca was known as the "mother of saints" because most of her children entered religious life, many were later recognized as saints, and several of her sons became bishops.

The Bishop of Ardagh was a separate episcopal title which took its name after the village of Ardagh, County Longford in Ireland. It was used by the Roman Catholic Church until 1756, and intermittently by the Church of Ireland until 1839.