In the fiction of J. R. R. Tolkien, Maglor was a Noldorin Elf of Middle-earth, one of the ill-fated sons of Fëanor. His father name in Quenya was "Kanafinwë", "strong-voiced". His mother name was "Makalaurë", "Forging Gold". Both names probably referred to his voice and harping. He was the greatest poet and bard among the Noldor, and among the Eldar only second to Daeron of Doriath.

Bound by the Oath of Fëanor, like all of his brothers, he went to Middle-earth with the host of the Noldor. He was noted as the fairest singer of all of the Noldor.

At the end of the conflict over the Silmarils, he took part in the attempts of the sons of Fëanor to regain by force the Silmaril that Beren and Luthien had rescued. In the second battle, he captured Elrond and Elros, the children of Earendil and Elwing; and though the Silmaril escaped him and his brothers, he raised the children as best he could because the endless fighting had sickened him. When in the end the war was ended by the Valar, Maglor and Maedhros alone remained; and Maglor eventually agreed to aid his brother in stealing the last two remaining Silmarilli. However, once gained the jewel burned his hand, and he cast the gem into the sea. Thereafter he wandered, singing along the shores of the world until he faded into memory.