Glóin is a the name of two fictional characters of J. R. R. Tolkien's fantasy world of Middle-earth.

Glóin was the son of Thorin I, and succeeded his father as the king of Durin's folk. He expanded the mines of the Ered Mithrin, and further abandoned Erebor.

A much later Glóin was the father of Gimli and was one of Thorin Oakenshield's companions in The Hobbit. He was the son of Gróin, the grandson of Borin, the younger son of King Náin II, and so could claim direct descent from Durin the Deathless himself. Óin, another of Thorin's companions, was his brother.