Aldamir, Quenya for tree-jewel (alda = tree, mir = jewel) is the twenty-third King of Gondor (Castamir being counted the twenty-second).
He was the second son of King Eldacar of Gondor and succeeded him in T.A. 1490 because his elder brother Ornendil was executed by Castamir.
His fifty year reign was marked with constant warfare with the Corsairs of Umbar (among them were the sons of Castamir) and the Haradrim.
In T.A. 1540 he was slain and was succeeded by his son Vinyarion.