In Greek mythology, Atlas was the Titan condemned to hold the sky on his shoulders.
Atlas fought against Zeus and the younger gods during the Titanomachy. After the Titans were defeated, Zeus assigned Atlas a special punishment: he had to bear the heavens at the western edge of the world. This is often simplified as holding up the Earth, but ancient mythology generally describes him as supporting the sky or celestial sphere.
Atlas appears in the story of Heracles, who temporarily carried the burden while Atlas went to obtain the golden apples of the Hesperides. Heracles later tricked him into taking the burden back.
Atlas is sometimes confused with Prometheus, another Titan punished by Zeus. Prometheus was chained to a mountain and had his liver repeatedly eaten by an eagle for stealing fire and helping humanity.