In ancient Greek religion and mythology, Pluto () was the ruler of the underworld. The earlier name for the god was Hades, which became more common as the name of the underworld itself. Pluto represents a more positive concept of the god who presides over the afterlife. Ploutōn was frequently conflated with Ploûtos, the Greek god of wealth, because mineral wealth was found underground, and because as a chthonic god Pluto ruled the deep earth that contained the seeds necessary for a bountiful harvest.William Hansen, Classical Mythology: A Guide to the Mythical World of the Greeks and Romans (Oxford University Press, 2005), p. 182. The name Ploutōn came into widespread usage with the Eleusinian Mysteries, in which Pluto was venerated as both a stern ruler and a loving husband to Persephone. The couple received souls in the afterlife and are invoked together in religious inscriptions, being referred to as Plouton and as Kore respectively. Hades, by contrast, had few temples and religious practices associated with him, and he is portrayed as the dark and violent abductor of Persephone.

Pluto and Hades differ in character, but they are not distinct figures and share two dominant myths. In Greek cosmogony, the god received the rule of the underworld in a three-way division of sovereignty over the world, with his brother Zeus ruling the sky and his other brother Poseidon sovereign over the sea. His central narrative in myth is of him abducting Persephone to be his wife and the queen of his realm.Hansen, Classical Mythology, p. 180. Plouton as the name of the ruler of the underworld first appears in Greek literature of the Classical period, in the works of the Athenian playwrights and of the philosopher Plato, who is the major Greek source on its significance. Under the name Pluto, the god appears in other myths in a secondary role, mostly as the possessor of a quest-object, and especially in the descent of Orpheus or other heroes to the underworld.Hansen, Classical Mythology, pp. 180–181.

Plūtō (; genitive Plūtōnis) is the Latinized form of the Greek Plouton. Pluto's Roman equivalent is Dis Pater, whose name is most often taken to mean "Rich Father" and is perhaps a direct translation of Plouton. Pluto was also identified with the obscure Roman Orcus, like Hades the name of both a god of the underworld and the underworld as a place. Pluto (Pluton in French and German, Plutone in Italian) becomes the most common name for the classical ruler of the underworld in subsequent Western literature and other art forms.

Hesiod

The name Plouton does not appear in Greek literature of the Archaic period.Lewis Richard Farnell, The Cults of the Greek States (Clarendon Press, 1907), vol. 3, p. 281. In Hesiod's Theogony, the six children of Cronus and Rhea are Zeus, Hera, Poseidon, Hades, Demeter, and Hestia. The male children divide the world into three realms. Hades takes Persephone by force from her mother Demeter, with the consent of Zeus. Ploutos, "Wealth," appears in the Theogony as the child of Demeter and Iasion: "fine Plutus, who goes upon the whole earth and the broad back of the sea, and whoever meets him and comes into his hands, that man he makes rich, and he bestows much wealth upon him." The union of Demeter and Iasion, described also in the Odyssey,Odyssey 5.125–128: And so it was when Demeter of the lovely hair, yielding / to her desire, lay down with Iasion and loved him / in a thrice-turned field (translation of Richmond Lattimore). took place in a fallow field that had been ploughed three times, in what seems to be a reference to a ritual copulation or sympathetic magic to ensure the earth's fertility.Hesiod, Theogony 969–74; Apostolos N. Athanassakis, Hesiod. Theogony, Works and Days, Shield (Johns Hopkins University Press, 1983, 2004), p. 56. "The resemblance of the name Ploutos to Plouton ...," it has been noted, "cannot be accidental. Plouton is lord of the dead, but as Persephone's husband he has serious claims to the powers of fertility."Athanassakis, Hesiod, p. 56. Demeter's son Plutus merges in the narrative tradition with her son-in-law Pluto, redefining the implacable chariot-driver Hades whose horses trample the flowering earth.Emily Vermeule, Aspects of Death in Early Greek Art and Poetry (University of California Press, 1979), pp. 37, 219; Hendrik Wagenvoort, "The Origin of the Ludi Saeculares," in Studies in Roman Literature, Culture and Religion (Brill, 1956), p. 198.

That the underworld god was associated early on with success in agricultural activity is already evident in Hesiod's Works and Days, line 465–469: "Pray to Zeus of the Earth and to pure Demeter to make Demeter's holy grain sound and heavy, when first you begin ploughing, when you hold in your hand the end of the plough-tail and bring down your stick on the backs of the oxen as they draw on the pole-bar by the yoke-straps."Hesiod, Works and Days 465–9.

Plouton and Ploutos

Plouton was one of several euphemistic names for Hades, described in the Iliad as the god most hateful to mortals.Hansen, Classical Mythology, pp. 162 and 182, citing Homer, Iliad 9.158–159. Euphemism is a characteristic way of speaking of divine figures associated with the dead and the underworld; Joseph William Hewitt, "The Propitiation of Zeus," Harvard Studies in Classical Philology 19 (1908), p. 66, considers euphemism a form of propitiation. Plato says that people prefer the name Plouton, "giver of wealth," because the name of Hades is fear-provoking.Plato, Cratylus 403a; Glenn R. Morrow, Plato's Cretan City: A Historical Interpretation of the Laws (Princeton University Press, 1993), pp. 452–453. The name was understood as referring to "the boundless riches of the earth, both the crops on its surface—he was originally a god of the land—and the mines hidden within it."Fernando Navarro Antolin, Lygdamus: Corpus Tibullianum III.1–6, Lygdami Elegiarum Liber (Brill, 1996), pp. 145–146. What is sometimes taken as "confusion" of the two gods Plouton and Ploutos ("Wealth") held or acquired a theological significance in antiquity. As a lord of abundance or riches, Pluto expresses the aspect of the underworld god that was positive, symbolized in art by the "horn of plenty" (cornucopia),Charlotte R. Long, The Twelve Gods of Greece and Rome (Brill, 1987), p. 179; Phyllis Pray Bober, "Cernunnos: Origin and Transformation of a Celtic Divinity," American Journal of Archaeology 55 (1951), p. 28, examples in Greek and Roman art in note 98; Hewitt, "The Propitiation of Zeus," p. 65. by means of which Plouton is distinguished from the gloomier Hades.Tsagalis, Inscribing Sorrow, pp. 101–102; Morrow, Plato's Cretan City, pp. 452–453; John J. Hermann, Jr., "Demeter-Isis or the Egyptian Demeter? A Graeco-Roman Sculpture from an Egyptian Workshop in Boston" in Jahrbuch des Deutschen Archäologischen Instituts 114 (1999), p. 88.

The Roman poet Ennius (ca. 239–169 BC), the leading figure in the Hellenization of Latin literature, considered Pluto a Greek god to be explained in terms of the Roman equivalents Dis Pater and Orcus.Pluto Latine est Dis pater, alii Orcum vocant ("In Latin, Pluto is Dis Pater; others call him Orcus"): Ennius, Euhemerus frg. 7 in the edition of Vahlen = Var. 78 = E.H. Warmington, Remains of Old Latin (Heinemann, 1940), vol. 1, p. 421. The Augustan poet Horace retains the Greek accusative form of the noun (Plutona instead of Latin Plutonem) at Carmen 2.14.7, as noted by John Conington, P. Vergili Maronis Opera (London, 1883), vol. 3, p. 36. It is unclear whether Pluto had a literary presence in Rome before Ennius. Some scholars think that rituals and beliefs pertaining to Pluto entered Roman culture with the establishment of the Saecular Games in 249 BC, and that Dis pater was only a translation of Plouton.H.D. Jocelyn, The Tragedies of Ennius (Cambridge University Press, 1967), p. 331, with reference to Kurt Latte, Römische Religionsgeschichte (C.H. Beck, 1967, 1992), p. 246ff. In the mid-1st century BC, Cicero identifies Pluto with Dis, explaining that "The earth in all its power and plenty is sacred to Father Dis, a name which is the same as Dives, 'The Wealthy One,' as is the Greek Plouton. This is because everything is born of the earth and returns to it again."Cicero, De natura deorum 2.66, translation of John MacDonald Ross (Penguin Books, 1972): Terrena autem vis omnis atque natura Diti patri dedicata est, qui dives, ut apud Graecos Πλούτων quia et recidunt omnia in terras et oriuntur e terris.

During the Roman Imperial era, the Greek geographer Strabo (1st century AD) makes a distinction between Pluto and Hades. In writing of the mineral wealth of ancient Iberia (Roman Spain), he says that among the Turdetani, it is "Pluto, and not Hades, who inhabits the region down below."Strabo 3.2.9, citing Poseidonius as his source, who in turn cites Demetrius of Phalerum on the silver mines of Attica, where "the people dig as strenuously as if they expected to bring up Pluto himself" (Loeb Classical Library translation, in the LacusCurtius edition). The 16th-century mythographer Natale Conti describes Pluto's imperium as "the Spains and all the places bordering the setting sun" (Mythologiae 2.9, edition of 1651, p. 173; cf. Strabo 3.12). In the discourse On Mourning by the Greek author Lucian (2nd century AD), Pluto's "wealth" is the dead he rules over in the abyss (chasma); the name Hades is reserved for the underworld itself.Lucian, On Mourning (see Greek text); Peter Bolt, Jesus' Defeat of Death: Persuading Mark's Early Readers (Cambridge University Press, 2003) discusses this passage (pp. 126–127) and Greco-Roman concepts of the underworld as a context for Christian eschatology passim.

Other identifications