Galdor is the name of one or two fictional characters from J. R. R. Tolkien's Middle-earth legendarium.

During the First Age, Galdor was a Ñoldorin Elf, who lived in Gondolin during the First Age, and was the leader of the Folk of the Tree. He was said to be the bravest Elf of Gondolin, save king Turgon himself. After the Fall of Gondolin he fled southwards to the Mouths of Sirion. It is said he later returned to the Undying Lands, and dwelt on Tol Eressëa.

During the Third Age, a Galdor of the Havens lived with Círdan in Mithlond. He was Círdan's messenger to the Council of Elrond.

In late writings (see: The History of Middle-earth), Tolkien speculated that the two Galdors may have been the same, but he ultimately rejected the notion: if Galdor had remained behind, he would either have completely rejected the call of the Valar, and thus have Fallen, or he would have had to leave and then return like Glorfindel did, which would make him a far more powerful person than his appearance in The Lord of the Rings suggests. For this reason Tolkien speculated that "Galdor" was simply a common Sindarin name. See The Peoples of Middle-earth.