Oceanus (Okeanos) occupies a distinctive position in the depth-psychology corpus: not merely a geographical or mythological cipher, but a primordial archetype of origin, encirclement, and the pre-personal ground of psychic life. Hillman, drawing on Onians, identifies Okeanos as the imageless, ever-moving source from which all archetypal figures arise — the ‘theon genesis,’ father of the gods who nonetheless remains absent from Olympus, sustaining the cosmos by holding it together. Onians supplies the etymological and cosmological scaffolding, demonstrating that Okeanos was conceived as the encircling bond of the earth, wound serpentine around the world-cylinder, and identified with the primal procreative liquid. Jung and Kerényi situate Oceanus within the broader mythologem of primordial waters and the cosmogonic self: the Gnostic text cited in Aion and Mysterium Coniunctionis identifies Oceanus with the unbegotten Man, ‘origin of gods and origin of men,’ a formula that resonates with alchemical conceptions of the prima materia. Kerényi historicizes the figure, tracing how Okeanos’s unlimited generative flux was curtailed and subordinated to Zeus, leaving only circular movement and the supply of springs. Across these voices, Oceanus functions as the depth-psychological correlate of the undifferentiated unconscious: boundless, pre-Olympian, fecund, and structurally irreducible to any single deity.