"Planet 51" is an animated sci-fi comedy that takes viewers on an intergalactic adventure filled with humor and heart. The story revolves around an alien named Lem, who lives a peaceful life on the titular Planet 51, a world that mirrors 1950s America. His tranquil existence is turned upside down when a human astronaut named Chuck Baker lands on the planet, mistakenly believing it to be uninhabited.

As Chuck tries to find a way back to his spaceship, he inadvertently becomes the target of the planet's paranoid military, who view him as a threat. With the help of Lem and his quirky group of friends, Chuck must navigate the challenges of being an outsider in a world that fears the unknown. Together, they embark on a hilarious journey filled with misadventures, ultimately teaching both aliens and humans the importance of friendship and acceptance.