Latin for "the Lion", from the Greek Leon. The Nemean Lion was another beast that Hercules disposed of. But like Cancer, why did Zeus elevate this beast to the heavens. Some tales state that the Nemean Lion was born of the chimera, or of Typhon and Echidna. However, the Lion's place in the Heavens is more easily explained by the tales that say that the Lion's parents were Zeus and Selene.

In Greek and Roman mythology,Leo is associated with Nemean the lion which was terrorizing the people of Nemes in ancient Greece. The first of Hercule's 12 labours was to slay the Nemean lion; Hercules strangled the lion in his den and skinned it, using the hide as his armour for the remaining 11 tasks. Hera, his mother, was so angry at his success that she raised the soul of the Lion high into the sky where today, it can be seen as the constellation of Leo.