Atlas, as described in Greek mythology, was the primordial Titan who supported the heavens.
In the war with the Olympians, Atlas sided with the Titans; when the Titans were defeated, Zeus condemned Atlas to stand at the western edge of Gaia (the Earth) and hold up Ouranos (the sky) to prevent the two from resuming their primordial embrace. A common misconception is that Atlas holds the Earth on his shoulders; classical art shows Atlas holding a Celestial Sphere, not a Globe.
During the Borg Invasion of 2381, Federation President Nanietta Bacco managed to gather an allied fleet at the Azure Nebula in an attempt to halt the Borg Collective's assaults. However, the fleet of several hundred vessels was all but wiped out by a fleet of over seven thousand Borg cubes; upon receiving the news, Bacco felt that the weight of her Presidency was akin to that of Atlas holding up the sky. (ST - Destiny novel: Mere Mortals)