According to one of our best sources for Greek mythology - the ancient poet Hesiod - Maia was one of the daughters of the Titan Atlas. Hesiod's Theogony includes the following information about Maia:
"Maia, daughter of Atlas, shared the sacred bed of Zeus
and gave birth to Hermes, renowned herald of the gods."
(Hesiod, Theogony, 938-939)
It is worth noting that other sources expand upon Hesiod's description of Maia's heritage, and state that she was a member of the Pleiades (the Pleiades were daughters of Atlas and Pleione). This means that Maia was the sister of some notable mythological characters, including Alcyone, Celaeno, Electra, Merope, Sterope, and Taygete.
Of course, the most famous myth about Maia involves her relationship with Zeus, the ruler of the Greek gods. Hesiod refers to this affair in his Theogony, as we have seen already in the previously quoted passage. It is also clear from this passage that the union of Maia and Zeus ended in a most fruitful outcome. For Maia obviously became pregnant and in time gave birth to the god Hermes.
One remarkable feature of the story of Maia's liaison with Zeus is the lack of interference by Hera, Zeus's notoriously jealous wife. Hera frequently punished the innocent paramours (and offspring) of Zeus in myth and legend. However, Hera did not seem as threatened by Maia and her divine son Hermes.
Who's Who in Classical Mythology