In the distant future, Earth has been trashed to the point of unsustainability. In response to this crisis, the megacorporation Buy-N-Large provides a solution to the problem: high-class cruise rocket ships that will bring mankind into outer space and leave the remnants of Earth to the Waste Allocation Load Lifter Earth-Class (WALL-E). These robots effectively work to clean the planet in humanity's place by compressing trash into portable cubes.

Now, only one WALL-E unit remains on Earth, living with a cockroach as its only companion. But a rocket soon crashes into its life, bringing EVE—a shiny new robot model—with it. With another potential friend around, the solitary robot's hopeless days now seem more colorful.