Liban was a minor sea goddess in Celtic mythology, probably originating from an ancient Manx deity. Along with her sister, Fand, she was a goddess of pleasure and health.

A daughter of King Ban and mother of illegitimate twins by Pandragus; wife of Labraid. Liban was one of the daughters of Eochaid and presumably of Etain. In the year 90 a sacred spring which had been sacrilegiously neglected overflowed its bounds and formed the great water of Lough Neagh. Eochaid and all his family were overwhelmed and drowned, except his two sons, Conang and Curman, and his daughter Liban. Liban was indeed swept away by the waters, but she and her pet dog were supernaturally preserved and carried into a subaqueous cave where she spent a year in her bower with no company except her little dog. She grew weary of this after a time, and prayed to God that she might be turned into a salmon and swim around with the shoals of fish that passed her bower. God so far granted her prayer as to give her the tail of a salmon, but from the navel upwards she retained the shape of a beautiful woman. Her dog was turned into an otter, and the two swam round together for 300 years or more. In this time Ireland had become Christian and St Comgall had become Bishop of Bangor. One day Comgall dispatched one of his clergy, Beoc, to Rome to consult Pope Gregory about some matters of order and rule. As they sailed they were accompanied by a very sweet voice singing from under the water. It was so sweet that Beoc thought that it must be an angel's voice. At that Liban spoke from under the water and said: 'It is I who am singing. I am no angel, but Liban the daughter of Eochaid, and for 300 years I have been swimming the seas, and I implore you to meet me, with the holy men of Bangor, at Inver Ollarba. I pray you tell St Comball what I have said, and let them all come with nets and boats to draw me out of the sea.' Beoc promised to do as she asked, pressed on on his errand, and before the year was over had returned from Rome, in time to tell St Comgall of Liban's prayer. On the appointed day a fleet of boats was there, and Liban was drawn out of the water by Beoan, son of Inli. They half-filled the boat in which she was caught with water, and crowds of people came to see her swimming around. A dispute arose as to who had the right to her. St Comgall thought she was his as she was caught in his diocese; Beoc claimed her because she had made her appeal to him; and even the man who had drawn her out of the sea staked his claim. To avoid dissension all the saints of Bangor embarked on a night of fasting and prayer. An angel spoke to them and said that on the next morning a yoke of two oxen would come to them. They were to put Liban into a chariot and harness the oxen to it; wherever they stopped, that was the territory. It was a method employed in many saints' legends to settle the place where a church should be erected, and the expedient did not fail this time. The oxen drew their chariot undoubtingly to Beoc's church, Teo-da-Beoc. There she was given her choice whether to die immediately and ascend at once to heaven or to stay on the earth as long as she had lived in the sea, and to ascend to heaven after 300 years. She chose immediate death. St Comgall baptized her by the name of Murgen, or 'sea-born', and she made her entry into heaven. She was accounted one of the Holy Virgins, and signs and wonders were done through her means in Teo-daBeoc.