In Greek mythology, King Gelanor (Ancient Greek: Γελάνωρ), of Argos welcomed Danaus and his daughters. When an oracle told him to give Danaus his kingdom, he did so. He wanted to sell the Danaides into slavery following their murder of their husbands, but Danaus and the gods dissuaded him. He is simply called the "King" in Aeschylus's Suppliant Maidens. Alternatively, it was not an oracle, but an omen, that induced Gelanōr to renounce his kinship in favor of Danaos. The omen was of a wolf attacking a herd of cattle grazing beside the city-wall, and killing the leading bull. His real name was Pelasgus, the name /Gelanōr/ is a literary devise meaning 'laughter' : he was so called because he had initially laughed at the claim to kingship over Argōs by Danaos. Gelanōr was son of Sthenelās.
In Helen of Troy, a novel by Margaret George, Gelanor is a fictional character who acts as an advisor to the Spartans under Menelaus. He accompanies Helen when she goes to Troy.