Keith is the commanding officer of the Voltron Lion Force and the pilot of the Black Lion. A former officer in the Galaxy Alliance's Galaxy Garrison Service, he was originally tasked with leading a scouting mission to locate Voltron on the planet Arus. His ship was shot down, and his team was captured by forces from the planet Doom before they managed to escape to Arus.

During a crossover event, Keith’s strong leadership and sense of duty are tested when Princess Allura’s soul is stolen by the witch Haggar and taken to a fear dimension. Vowing to rescue her, he journeys there aided by the ghost of King Alfor. In that dimension, he confronts the demons of his own childhood fears to face Haggar. Allura ultimately appeals to the hidden goodness within Haggar to secure their freedom and return to the Castle of Lions.

This mission forces Keith to conquer his longstanding, irrational fear of getting lost in forests, a fear that originated in his childhood. He also develops a personal rivalry with Prince Lotor, engaging him in a duel near the castle.

Following the successful rescue, Keith and the blue and black lions rejoin the battle against multiple Robeasts. Even after forming Voltron, the team struggles in combat until the arrival of the Vehicle Voltron force helps them gain the upper hand. The combined efforts of both Voltron teams are required to defeat the Robeasts after they combine into their own super robot.

After the victory, the two teams spend time together. Keith is a quiet individual who spends much time pondering decisions and devising new strategies. He is a protective figure, particularly towards Princess Allura, and is considered a well-balanced leader.