Celegorm was the third son of Feanor, and like the other children of Feanor, swore an oath to recover his Silmarils at any cost. The end result of this was that the sons of Feanor engaged in large-scale killings of their fellow Elves known as "kinslaying", fighting them the same way they fought the armies of Morgoth.
Celegorm was born in the Noontide of the Valinor. He grew up into a great huntsman, learning his trade from the Valar Orome the Hunter, who taught him how to best harness the birds and beasts of the world, as well as various languages. When he came to Middle-Earth, he brought with him from Valinor a special gift to him from Orome, a great hound named Huan.
Sadly, upon taking up the oath to recover his father's Silmarils no matter what, Celegorm began the hunt, engaging in mass kinslaying at Alqualonde, ensuring that he and his sibling Curufin would never be welcome there again. Their conflicts against Morgoth also went poorly for them in the long run, with Morgoth launching a surprise attack on Dagor Bragollach. Forced to flee, they eventually settled in Nargothrond. Whilst there, Celegorm became quite taken with the beautiful half-Elf, half-Maiar Luthien, and so he and Curufin kidnapped her. They intended to force her father to consent to let her marry him in the hopes of both getting Luthien for Celegorm, and also forming a new alliance with a powerful Elf queen.
But, Celegorm's hound Huan turned on his master and helped Luthien escape. Celegorm and Curufin were then expelled from Nargothrond and forced to leave again. During the Second Kinslaying, Celegorm, Curufin, and Caranthir attacked the Elven king Dior to take the Silmaril that he then had. All three of the siblings perished in that battle, though Celegorm at least did manage to take Dior with him, the two slaying each-other in the halls of Menegroth.
- He is described as having fair hair, which is unusual, as his parents and siblings all had either black hair or red hair.