During preproduction, an early version of WALL•E, then called "Trash Planet" and pitched by Pete Docter, involved "some aliens that come down to the planet and speak a little bit like the two aliens on Sesame Street that go 'yip-yip-yip-yip'."
- Bob Bergen provided additional voices
- Ben Burtt designed all of the robot voices and mechanical sounds and voiced WALL•E and M-O
- John Lasseter was the executive producer
- Kathy Najimy voiced Mary
- Laraine Newman provided additional voices
- Sigourney Weaver voiced "computer"
- Fred Willard played BnL CEO Shelby Forthright