[3] Like her husband, Theia features scarcely in myth, being mostly important for the children she bore, though she appears in some texts and rare traditions.

Early accounts gave her a primal origin, said to be the eldest daughter of Gaia (Earth) and Uranus (Sky).

[4] She is thus the sister of the Titans (Oceanus, Crius, Hyperion, Iapetus, Coeus, Themis, Rhea, Phoebe, Tethys, Mnemosyne, Cronus, and sometimes of Dione), the Cyclopes, the Hecatoncheires, the Giants, the Meliae, the Erinyes, and is the half-sister of Aphrodite (in some versions), Typhon, Python, Pontus, Thaumas, Phorcys, Nereus, Eurybia, and Ceto.

[5] Robert Graves relates that Theia is referred to as the cow-eyed Euryphaessa who gave birth to Helios in myths dating to classical antiquity.

[15] In the east Gigantomachy frieze of the Pergamon Altar, the figure of the goddess preserved fighting a youthful giant next to Helios is conjectured to be his mother Theia.