In ancient Greek religion and mythology, Pluto was the ruler of the Greek 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. 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.

In Greek mythology, the Greek underworld, or Hades, is a distinct realm where an individual goes after death. The earliest idea of afterlife in Greek myth is that, at the moment of death, an individual's essence (psyche) is separated from the corpse and transported to the underworld. In early mythology the dead were indiscriminately grouped together and led a shadowy post-existence; however, in later mythology elements of post-mortem judgment began to emerge with good and bad people being separated.