It is argued that Copernican astronomy is a key theme in Michelangelo's fresco of the Last Judgment in the Sistine Chapel, and was incorporated with the knowledge, consent and approval of the Popes concerned. In Christian art, the iconography of the Last Judgment (depicting the three parts of the universe: heaven, Earth and hell) was traditionally based on a layered structure relating to perceptions of the flat Earth covered by the dome of heaven according to biblical cosmology. In Michelangelo's revolutionary work, Christ is significantly depicted as a beardless Apollonian Sun-god, positioned in the centre of a dramatic circular design rather than at the top of a layered format. This appears to relate to the traditional Christian analogy between the deity and the astronomical feature of the sun, the neoplatonic cult of Sun-symbolism and sources in Dante. More importantly, the influence of the Copernican theory of heliocentricity is argued, since interest in such ideas in papal circles is demonstrated at exactly the time of the commission of the painting (1533). This provides important evidence of papal support for Copernican heliocentricity as early as the 1530s.