Calypso, in Greek mythology, the daughter of the Titan Atlas (or Oceanus or Nereus), a nymph of the mythical island of Ogygia. In Homer’s Odyssey, Book V (also Books I and VII), she entertained the Greek hero Odysseus for seven years, but she could not overcome his longing for home even by promising him immortality. At last the god Hermes was sent by Zeus, the king of the gods, to ask her to release Odysseus. According to Hesiod’s Theogony, she bore Odysseus twin sons, Nausithous and Nausinous.