Bórin II was a dwarf who lived in the Iron Hills under the rule of Dáin Ironfoot. He was the second son of Balin and Lilia, the younger brother of Burin, and nephew of Dwálin. Named after Bórin I, Bórin II was among the Dwarves of the Iron Hills that answered to Dáin's call and accompanied him to travel north-west to Erebor and engage Azog's armies in the battle.
After surviving the war, Bórin was among the dwarves that accompanied Balin as part of his colony to reclaim Khazad-Dûm. The plan was a success and Bórin would stay in the ancient city to uncover a lot of things that were left behind. However, as years passed, he was among the dwarves slain when Orcs had managed to reclaim Moria.