Idril Celebrindal (Years of the Trees 1469 – First Age 524, aged approx. 820 years when she sailed towards Valinor) was the daughter of King Turgon of Gondolin and Elenwë, wife of Tuor, and the mother of Eärendil the Mariner.
Idril Celebrindal was the only child of Turgon. She participated in the Flight of the Noldor, and in the Helcaraxë almost lost her life falling through the ice with several others, but Turgon saved her, though he lost his wife Elenwë. Together with Angrod's son Orodreth she was one of the two Noldor in the third generation to come into exile. Idril was loved in secret by her cousin Maeglin, the son of Eöl the Dark Elf and Aredhel, Turgon's sister, but she scorned his advances because of his dark character, and the fact they were too closely related.
When Tuor, son of Huor arrived in Gondolin, Idril fell in love with him. Because Turgon had grown to love Tuor as a son (as he had his father before), and remembering the last words of Huor, he allowed Idril and Tuor to wed, thus bringing about the second union of Men and Elves, after Beren and Lúthien. Idril encouraged Tuor to build the secret passage known as Idril's Secret Way, and thus enabled many to escape the Fall of Gondolin. In Gondolin she had a son, Eärendil.
When Tuor grew old he departed in his ship for the West, and Idril went with him. It is believed by the Elves and Dúnedain that Idril and Tuor arrived in Valinor, bypassing the Ban of the Valar, and that Tuor was reckoned in the kindred of the Elves, so that Tuor and Idril now live in Valinor.