Melian the Maia is a fictional character in the fantasy-world Middle-earth of the English author J. R. R. Tolkien. She appears in The Silmarillion, the epic poem The Lay of Leithian, The Children of Húrin, the Annals of Aman and the Grey Annals.
A visual description of Melian is given in the Lay of Leithian:
There Melian came, the Lady grey,
and dark and long her tresses lay,
beneath her silver girdle seat
and down unto her silver feet.
She is a Maia of the race of the Ainur, akin to Yavanna. Before the First Age, in the Years of the Trees, she leaves the gardens of Lórien and goes to Middle-earth, and there she falls in love with the Elven-king Elu Thingol, King Greymantle, and with him rules the kingdom of Doriath. She has a child with Thingol, a daughter named Lúthien, said to be the fairest and most beautiful of all the Children of Illúvatar (God). Melian's line of descent is the half-elven.
Thingol encounters Melian in the woods of Nan Elmoth and falls under Melian's enchantment of love for long, long years. As a result of his absence a portion of his followers stay behind to search for him, the rest continue on to Valinor. Melian and Thingol thereafter found the kingdom of Doriath in Middle-earth. Their daughter Lúthien Tinúviel, marries the man Beren. As a result Melian's Maian blood passed to both Elves and Men.
When war with the Great Enemy, Morgoth, comes to Doriath she uses her powers to guard and defend it with a protection called List Melian, the Girdle of Melian. Its magic mazes of mists prevent anyone less powerful than Melian from entering the kingdom. However, with the foresight of a Maia, she predicts that one day someone whose fate is more powerful will enter. When Beren arrives as foretold, she counsels Thingol against sending Beren for a Silmaril, a quest which would eventually have a part in Doriath's ruin. This is one of many instances in which she proves, through her wisdom and powers of foresight, to be wiser than her husband, and an effective queen of her land. The great, evil Wolf, Carcharoth also passes the Girdle. In Doriath she also becomes a friend and tutor of Galadriel to whom she teaches the art of Lembas-baking. After the departure of Lúthien and Beren, she aides Túrin and his mother and sister. She provides Beleg with way-bread, Lembas, and foresees his doom in his quest for Túrin. When Húrin returns she is the one to lift the spell of Morgoth from him.
After Thingol's death, she vanishes from Middle-earth, passing to Valinor, where she mourns the loss of her husband to the Halls of Mandos and daughter to the unknown fate of human death.
Melian and Thingol were a unique couple, the only case where an Ainu married any Elf or Human. Melian is also the only Ainu known to have had children in the "official" drafts of Tolkien's work, though there are some creatures who have reproduced, like Ungoliant, whose exact natures are unclear.