Cast and characters
- Ben Burtt produced the voice of WALL-E (Waste Allocation Load Lifter – Earth Class), the title character. WALL-E, a robot who has developed sentience, is the only robot of "his" kind shown to be still functioning on Earth. He is a small mobile compactor box with all-terrain treads, three-fingered shovel hands, binocular eyes, and retractable solar cells for power. He collects spare parts for himself, which becomes pivotal to the plot, and replaces broken and/or worn out parts on-the-fly by cannibalizing "dead" WALL-Es. Although working diligently to fulfill his directive to clean up the garbage (all the while accompanied by his cockroach friend Hal and music playing from his on-board recorder) he is distracted by his curiosity, collecting trinkets of interest. He stores and displays these "treasures" such as a birdcage full of rubber ducks, a Rubik's Cube, Zippo lighters, disposable cups filled with plastic cutlery and a golden trophy at his home where he examines and categorizes his finds while watching video cassettes of musicals via an iPod viewed through a huge magnifier.
- Burtt is also credited for the voice of M-O (Microbe Obliterator), as well as most of the other robots. M-O is a tiny, obsessive compulsive maintenance robot with rollers for hands who keeps Axiom clean. When M-O meets WALL-E and sees how filthy he is, he deviates from his normal routine and follows WALL-E, cleaning up behind him. When he follows WALL-E to the garbage bay, he inadvertently but fortuitously saves WALL-E and EVE from being blown into the vacuum of space. He then forms a close friendship with Wall-E and aids the two in retrieving the plant, most notably through using his contaminant detecting vision when Wall-E drops the plant. back on Earth, he ushers the other robots into giving WALL•E and EVE some privacy as they share a tender moment.
- Elissa Knight as EVE (Extraterrestrial Vegetation Evaluator), a sleek robot probe whose directive is to locate vegetation on Earth and verify habitability. She has a glossy white egg-shaped body and blue LED eyes. She moves using antigravity technology and is equipped with scanners, specimen storage and a plasma cannon in her arm, which she is quick to use. When first deployed on Earth she appears devoid of feeling but as the craft that delivered her blasts off and away she springs to life with gleeful flight. Watching her, WALL-E accidentally draws her attention as she sets about following her directive growing ever more impatient with both her lack of success and with WALL-E's constant monitoring. This shared strength of feeling soon connects the two characters.
- Jeff Garlin as Captain B. McCrea, the commander, and apparently only, officer on the Axiom. His duties as captain are boring daily routines, with the ship's autopilot handling all true command functions. Meeting WALL-E, however, sparks his interest in Earth and he becomes engrossed in researching the home planet, paving the way for his retaking control of the ship back from the Autopilot.
- Fred Willard as Shelby Forthright, historical CEO of the Buy n Large Corporation, shown only in videos recorded around the time of the Axiom's initial launch. Constantly optimistic, Forthright proposed the evacuation plans, then to clean up and recolonize the planet. However, the corporation gave up after realizing how toxic Earth had become. Forthright is the only live action character with a speaking role, the first in any Pixar film.
- MacInTalk, the text-to-speech program for the Apple Macintosh, was used for the voice of Auto, the rogue autopilot artificial intelligence built into the ship. Unlike other robots in the film, Auto is not influenced by WALL-E, instead following directive A113, which is to prevent the Axiom and the humans from returning to Earth because of the toxicity, and he will prevent anyone from deviating from it. The robot's design is a homage to HAL 9000 from 2001: A Space Odyssey, featuring a HAL-style red "eye" in the center of his body.
- John Ratzenberger and Kathy Najimy as John and Mary, respectively. John and Mary both live on the Axiom and are so dependent on their personal video screens and automatic services that they are oblivious to their surroundings, for instance not noticing that the ship features a giant swimming pool. However, they are brought out of their trances after separate encounters with WALL-E, eventually meeting face-to-face for the first time.
- Sigourney Weaver as the voice of the Axiom's computer. Stanton joked about the role with Weaver, saying, "You realize you get to be 'Mother' now?" referring to the name of the ship's computer in the film Alien, which also starred Weaver.
M-O just finishes cleaning the floor.
Wally is fascinated.
Impishly makes another mark.
M-O compulsively cleans it. Can’t resist.
M-O (bleeps): [Look, it stays clean. You got that?]
Wally wipes the bottom of his tread on M-O’s face.
M-O loses it.
Scrubs his own face.
and as a guide to what the sound effects needed to convey