The term ‘Maternal Unconscious’ names a cluster of phenomena that depth-psychological writers treat not as a single doctrine but as a field of overlapping tensions: the archaic stratum of the psyche that is structured by, and continues to carry the imaginal weight of, the mother-relation. Jung establishes the foundational coordinates: the unconscious, particularly in men, bears a maternal character insofar as it is the ‘mother or matrix of consciousness,’ and the sea, water, wood, and cave all participate in this maternal symbolism. Neumann elaborates a developmental mythology in which the uroboric container, the Great Mother archetype, and the pre-ego condition of undifferentiated psychic life collectively constitute the maternal unconscious as the originary ground from which ego-consciousness must wrest itself. Harding tracks the same dynamic in concrete clinical terms—the unspoken, somatic channel between mother and child, through which the mother’s own unconscious contents are transmitted almost telekinetically. Rank approaches the question from the perinatal axis, arguing that the deepest layer of the unconscious retains the imprint of intrauterine existence and the birth trauma, making the maternal body the original template for regression, transference, and the longing for return. Winnicott and the object-relations tradition reframe the maternal unconscious in environmental terms: failures of ‘holding’ by the mother install structurally unconscious gaps in the emerging self. Across these positions, the decisive tension is between a transpersonal, archetypal reading and a relational-developmental one—between the maternal unconscious as cosmogonic depth and as the legacy of a specific dyadic history.