In Greek mythology, Phoroneus (Φορωνεύς) was a culture-hero of the Argolid, fire-bringer, primordial king of Argos and son of the river god Inachus and either Melia, the primordial ash-tree nymph or Argia, the embodiment of the Argolid itself: "Inachus, son of Oceanus, begat Phoroneus by his sister Argia," wrote Hyginus, in Fabulae 143. Hyginus' genealogy expresses the position of Phoroneus as one of the primordial men, whose local identities differed in the various regions of Greece, and who had for a mother the essential spirit of the very earth of Argos herself, Argia. He was the primordial king in the Peloponnesus, authorized by Zeus: "Formerly Zeus himself had ruled over men, but Hermes created a confusion of human speech, which spoiled Zeus' pleasure in this Rule". Phoroneus introduced both the worship of Hera and the use of fire and the forge. Poseidon and Hera had vied for the land: when the primeval waters had receded, Phoroneus "was the first to gather the people together into a community; for they had up to then been living as scattered and lonesome families". (Pausanias).
Phoroneus was said to have been married to Cinna, or Cerdo, or Teledice (or Laodice) the nymph, or Perimede, or first to Peitho and second to Europe, and to have fathered a number of children, some of whom are dealt with below; others include Car, Chthonia, Clymenus, Sparton, Lyrcus and Europs, an illegitimate son. An unnamed daughter of his is said to have consorted with Hecaterus.
In Argive culture, Niobe is associated with Phoroneus, sometimes as his mother, sometimes as his daughter, or else, likely, as his consort (Kerenyi). His successor was Argus, who was Niobe's son, either by Zeus or Phoroneus himself. He was also the father of Apis, who may have also ruled Argos (according to Tatiānus). He was worshipped in Argos with an eternal fire that was shown to Pausanias in the 2nd century CE, and funeral sacrifices were offered to him at his tomb-sanctuary.
In another story, according to Hellanicus of Lesbos, Phoroneus had at least three sons: Agenor, Jasus and Pelasgus, and that after the death of Phoroneus, the two elder brothers divided his dominions between themselves in such a manner that Pelasgus received the country about the river Erasmus, and built Larissa, and Iasus the country about Elis. After the death of these two, Agenor, the youngest, invaded their dominions, and thus became king of Argos.
Clement of Alexandria mentions Phthia, a daughter of Phoroneus, who became the mother of Achaeus by Zeus. This version is to some extent confirmed by Aelian, who relates that Zeus assumed the shape of a dove to seduce a certain Phthia.