Phaënon was a beautiful boy created by Prometheus. When Prometheus had moulded a man out of clay, he usually presented him to Zeus for the great god's approval. Since Phaënon was outstandingly good-looking, however, he neglected to send Phaënon for the usual check (perhaps because he knew of the god's fondness for beautiful boys).

Eros 'ratted' on this oversight, however, and Zeus promptly sent Hermes to fetch Phaënon. In the event Hermes managed to persuade Zeus that Phaënon would be better off as an 'immortal' and so carried him off to heaven where he became the planet Jupiter.

Some say, however, that Jupiter was called Phaëthon, and that Phaënon became the planet Saturn (see the names of both these planets). At all events, as befits handsome boy and glowing planet, his name means 'shining', from phaeno, 'to shine'. The story is told by Hyginus in his Poetica Astronomica.