Five Galaxy Alliance space explorers named Keith, Lance, Pidge, Hunk and Sven come upon Planey Arus which has been ravaged by the evil King Zarkon's forces. When they arrive, they are captured and taken to Planet Doom, where they are imprisoned. After their escape, they head back to Arus.

After making it to the ruins of the Castle of Lions, they convince the beautiful Princess Allura and her advisor, Coran, to allow them to seek out the five Lions of Voltron. From then on, they are known as the Voltron Lion Force and eventually succeed in driving Zarkon's forces back with Voltron's help.

The rest of the series focuses on the struggle to keep Arus free and secure from Zarkon's rules. Later, Sven is hurt by the evil witch Haggar, leading Allura to assume his place on the Force. Eventually, Zarkon's son, Prince Lotor, comes into the picture adding an interesting new romantic dimension to the show - he's hopelessly infatuated with Allura.

Hunk lives up to his nickname in size of body and heart. This pilot of the Yellow Lion hates seeing injustices brought onto innocent people. When forming Voltron, his Lion makes up the left leg.

Keith is the most level-headed member of Voltron Force. As Captain, he always puts the safety of his friends and planet Arus as first priority. He has feelings for Allura, which often distracts him from the task at hand. Dressed in red, Keith pilots the Black Lion, which makes up Voltron's head.

Sven was one of the original members of Voltron Force, serving as navigator and piloting the Blue Lion. However, after a battle with the evil witch Haggar early in the series, Sven was so badly injured that he was taken to the medical planet of Ebb. He later fell in love with Allura's distant cousin, Princess Romelle of Planet Pollux.

Standing 2nd in command, Lance is a bit of a hothead. He always has a snappy punch line or speedy pun about the enemies the Force has to fight. Dressed in blue, this member of the Voltron Force pilots the Red Lion, making up the right arm of Voltron.

Allura is the princess of the planet Arus, and her father, King Alfor, died in a battle with Zarkon. While at times, she seems naive, when called on, she can be one of the bravest on the team. Sven piloted the Blue Lion before her, but was severely injured by the witch Haggar, so Allura took his place. Allura has a crush on Keith and can be seen eyeing him and blushing when he's around.

This smart, techno-genius pilots the Green lion. He grew up on planet Balto, which Zarkon later destroyed. Despite his small stature, he is unafraid when facing enemies. Sporting a green uniform, his Lion makes up the left arm of Voltron.

Between King Zarkon, his troublesome son Prince Lotor, Commander Cossack and the evil Witch Haggar, the Voltron Force has their hands full fighting the forces of Planet Doom.