Dior is a fictional character in J. R. R. Tolkien's Middle-earth.

Dior was born to Beren and Lúthien. He is called Elúchil, Thingol's Heir. He had three children:

His sons Eluréd and Elurín were seized at the Sack of Menegroth and left to die in the woods of Doriath by Caranthir the Dark, one of the sons of Fëanor. (Caranthir's brother Maedhros repented of this deed by vainly yet desperately searching for them in the forests.) His daughter Elwing, however, went on to marry Earendil the Mariner and helped to end the suffering of Middle-earth on more than one level: she was a messenger to Valinor which brought on the War of Wrath, thus destroying Morgoth's dominion; and she gave birth to Elrond and Elros, without whom (and their descendants) Sauron the Abhorred would have his own dominion.