Chthonic religion — the complex of cults, deities, sacrificial forms, and cosmological orientations that root themselves in the earth, the underworld, and the powers below — occupies a structurally pivotal position within the depth-psychology corpus. The classical scholars whose work feeds this library (Rohde, Burkert, Harrison, Campbell, Padel) map the chthonic as a distinct ritual and theological register opposed to, yet entangled with, the Olympian sky-religion. Rohde insists that chthonic powers carry genuine fructifying force and cannot be reduced to mere agents of death and destruction. Burkert documents the formal Greek vocabulary — chthonic Demeter, chthonic Dionysos, chthonic Zeus, Hecate, Hermes — showing how the epithet organizes a coherent sacrificial economy alongside Olympian cult. Harrison excavates the pre-Olympian substrate of Greek religion, arguing that earth-forces must be purged of violence before fertility can freely manifest, a drama enacted at oracular centers like Delphi. Campbell, drawing on Harrison, amplifies the psychological contrast between upward-directed Olympian rite and downward-directed chthonic rite with its trench-libations and do ut abeas logic. For depth psychologists — Jung, Hillman, Neumann, Greene — ‘chthonic’ migrates inward: the serpent as chthonic daemon, the underworld as the realm that dreams inhabit, the Great Mother as sovereign of chthonic instinct. The term thus bridges classical scholarship and archetypal psychology, functioning as both historical category and ontological metaphor for the unconscious substrate of psychic life.