She was a daughter of Nereus and Doris—thus a Nereid— according to Hesiod's Theogony but of Oceanus and Tethys—thus an Oceanid— according to Apollodorus, who actually lists her both among the Nereids and also among the Oceanids. She is not fully personified in the Homeric epics: "out on the open sea, in Amphitrite's breakers" (Odyssey iii.101); her Homeric epithet Halosydne ("sea-nourished") she shares with Thetis in some sense the sea-nymphs are doublets.
Amphitrite, "the third one who encircles (the sea)", was so entirely confined in her authority to the sea and the creatures in it, that she was all but never associated with her husband either for purposes of worship or in works of art, except when he was to be distinctly regarded as the god who controlled the sea: an exception may be the cult image of Amphitrite that Pausanias saw in the temple of Poseidon at the Isthmus of Corinth (ii.1.7). Though Amphitrite does not figure in Greek cultus, at an archaic stage she was of importance, for in the Homeric Hymn to Delian Apollo, she appears at the birthing of Apollo among "all the chiefest of the goddesses, Dione and Rhea and Ichnaea and Themis and loud-moaning Amphitrite." The deeply-knowledgable Pindar, in his sixth Olympian Ode, recognized Poseidon's role as "great god of the sea, husband of Amphitrite, goddess of the golden spindle." For later poets, Amphitrite was simply a metaphor for the sea: Euripides, in Cyclops (702) and Ovid, Metamorphoses, (i.14).
In the arts, Amphitrite was distinguishable from the other Nereids only by her queenly attributes. It was said that Poseidon first saw her dancing at Naxos among the other Nereids and carried her off. But in another version of the myth, she fled from his advances to Atlas, at the farthest ends of the sea; there the dolphin of Poseidon found her, and was rewarded by being placed among the stars.
Amphitrite's brood included seals and dolphins. Poseidon had one son by Amphitrite, Triton and a daughter, Rhode (if this Rhode was not actually fathered by Poseidon on Halia or was not the daughter of Asopus as others claim.) Apollodorus (3.15.4) also mentions a daughter of Poseidon and Amphitrite named Benthesikyme.
In works of art Amphitrite is represented either enthroned beside him, or driving with him in a chariot drawn by sea-horses (hippocamps) or other fabulous creatures of the deep, and attended by Triton and Nereids. She is dressed in queenly robes and has nets in her hair. The pincers of a crab are sometimes shown attached to her temples.