Melian [ˈmeli.an] the Maia is a fictional character in J. R. R. Tolkien's legendarium. She appears in The Silmarillion, the epic poem The Lay of Leithian and the novel The Children of Húrin.
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,and down unto her silver feet.
beneath her silver girdle seat
She is a Maia of the race of the Ainur, akin to Yavanna. Before the First Age, in the Years of the Trees, she left the gardens of Lórien and went to Middle-earth, and there she fell in love with the Elven-king Elu Thingol, King Greymantle, and with him ruled the kingdom of Doriath. She had a child with Thingol, a daughter named Lúthien, said to be the fairest and most beautiful of all the Children of Ilúvatar. Melian's line of descent is the half-elven and Kings of Númenor.
Her name Melian means Beloved in Tolkien's invented language of Sindarin. In Quenya, another of Tolkien's languages, it translates to "Melyanna", either "Dear Gift" or "Gift of Love" (Q. melya, "dear, lovely" < Q. mel-, "love"; Q. anna, "gift").
Thingol encountered Melian in the woods of Nan Elmoth and fell in love with her. As a result of his absence, a portion of his followers stayed behind to search for him; the rest continued on to Valinor. Melian and Thingol thereafter founded the kingdom of Doriath in Middle-earth. Their daughter Lúthien Tinúviel married Beren, who was human. As a result, Melian's Maian blood passed to both Elves and Men.
When war with the Great Enemy, Morgoth, came to Doriath, she used her powers to guard and defend it with a protection called the Girdle of Melian (List Melian in Sindarin). Its magic mazes of mists prevented anyone from entering the kingdom without her or Thingol's consent, as long as they were less powerful than her. With the foresight of a Maia, she predicted that one day someone whose fate is more powerful would enter. When Beren arrived as foretold, she counseled 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 proved, 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 passed the Girdle. In Doriath she also became a friend and tutor of Galadriel, to whom she taught the art of making lembas. After Lúthien and Beren departed to Valinor, Melian aided Túrin and his mother and sister. She provided Beleg with way-bread, lembas, and foresaw his doom in his quest for Túrin. When Húrin returned she was the one to lift the spell of Morgoth from him.
After Thingol's death, she vanished from Middle-earth, passing to Valinor, where she mourned the loss of her husband to the Halls of Mandos and the loss of her 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.
In the early legendarium Melian is defined as a fay, making her somewhat more sinister than in her later appearance. This version of her is presented in the Tale of Tinúviel, Tolkien's first story of Beren and Lúthien, which was written in archaic English and published in the second part of the Book of Lost Tales. In this work she appears in another later narrative and her character is portrayed as being far weaker and more frail than her later manifestation.