The Goddess Substrate designates, within the depth-psychological and mythological literature, that primordial, undifferentiated feminine ground from which specific divine figures, cosmic orders, and cultural formations are held to arise. The corpus reveals two broad analytical orientations. The first, represented most comprehensively by Neumann and extended by Campbell, Harvey, and Baring, treats this substrate as an archetypal psychic reality — a pre-patriarchal stratum in which the Great Mother presides as simultaneous source, container, and destroyer of all manifest being. The Great Goddess, in this reading, is not one deity among others but the ontological matrix underlying all mythological differentiation, whether expressed as Inanna, Demeter, Kali, or the unnamed Paleolithic feminine. The second orientation, visible in Zimmer’s Indological scholarship and Kerényi’s Greek mythography, approaches the substrate more historically and phenomenologically, tracing the persistence of pre-Olympian and Vedic feminine figures as structural substrata beneath later, patriarchally organized pantheons. A significant tension runs throughout: whether the Goddess Substrate is best understood as a universal psychic archetype (Jung–Neumann lineage) or as a recoverable historical–religious layer progressively suppressed but never fully extinguished. Campbell occupies both positions, grounding mythological analysis in comparative religion while affirming the archetype’s psychological sovereignty. The term thus marks an intersection of myth, depth psychology, archaeology, and feminist theology whose stakes remain actively contested.