Laïus was the son of Labdacus. After an infatuation with the young boy Chrysippus, whom he kidnapped, he became the first husband of Jocasta, who bore him Oedipus. His name is so 'elemental' that a number of derivations can be proposed for him, all apt. Since the Thebans called him to the throne on the death of Zethus (who had usurped it), his name could be a shortened form of Laomedon and so be 'king of the people'.

It could also be interpreted as 'unlucky', from laios, 'left', since his fate was to be killed by Oedipus, who was not aware that Laïus was his father. On similar sinister lines his name could be linked with that of Lethe, since Laïus was a kind of emblem of darkness. Or it could simply be a propitious name, from lets, 'herd of cattle', meaning 'one who is rich in cattle'.