GoLion's story is set in 1999, when the planet Altea is subdued and enslaved by the Galra Empire. Meanwhile, five space pilots (Akira Kogane, Takashi Shirogane, Isamu Kurogane, Tsuyoshi Seidou and Hiroshi Suzuichi) return to Earth from their latest space exploration, only to find the planet annihilated by an apocalyptic, thermonuclear war, World War III. Suddenly, the explorers are ambushed, captured and enslaved by the visiting Galra Empire, and then, they are forced to fight for their lives in Emperor Daibazaal's arena.

The young pilots escape and eventually land on the planet Altea, where they discover the secret of the mighty sentient robot GoLion, the only weapon powerful enough to defeat Emperor Daibazaal's forces. Thousands of years ago, GoLion was an arrogant robot who, after defeating several Beastmen, tried to challenge the goddess of the universe into battle, but failed. For GoLion's hubris, the goddess taught him humility by separating him into five pieces in the form of five lion robots that sailed through space and crash-landed on Altea, to lay in wait for those who would one day reawaken him to fight evil once again.[1][2][3] The Princess of Altea, Fala, recruits the five of them so they can become the new pilots of GoLion and help her start fighting back against the Empire.