Before she came to Middle-earth, Melian served both Vána and Estë, and dwelt in Lórien tending the trees that grew in the Gardens of Irmo. Among all of her people none were wiser, more beautiful, or more skilled in singing enchanting songs than Melian. During her time in Middle-earth, Melian was deeply in love with the shadows of the great trees. When the light of the Two Trees would begin to mingle, she would sing as the Valar would stop their work and listen. There, she would teach them her song Of all the Valar she was most akin to was Yavanna. When the elves awoke on the shore of Cuiviénen, Melian departed from Valinor and went to Middle-earth, where she filled its silence with her singing of the birds.
While in the forest of Nan Elmoth, Melian fell in love with the Elven-king Elu Thingol. There, she married him and became the ruler of Doriath. For thousands of years, she used her powers to guard and defend the city with a protection spell called the Girdle of Melian, but she predicted that one person would one day breach this defense. This was when Melkor would plan to take this advantage since he feared her. Before that happened, Melian and Elu had a child, a daughter named Lúthien. During her stay in Doriath, she became a friend and mentor of Lady Galadriel.
Melian's main line of descent became known as the Half-elves, and through her daughter, Maiar blood passed to both Elves and Men. When Beren Erchamion, arrived as foretold, Melian warned Thingol about sending Beren for a Silmaril, a quest which would eventually lead to Doriath's ruin. A friend of man-kind, she also aided Húrin's family by hosting Túrin in Doriath and later helped Beleg Cúthalion in his search for Túrin by giving him Lembas. When Húrin came to Doriath old and carrying a great grief and misery on him, Melian helped him see through his ills. After Thingol's death, Melian left Doriath, and went back to Valinor, musing upon her sorrows in the gardens of Lorien whence she came. Her spirit later reunited with her husband later on.