Cartwright also voices other characters for the show, including Maggie Simpson, Ralph Wiggum, Todd Flanders, and Nelson Muntz.

In 1987, Cartwright auditioned for a role in a series of animated shorts about a dysfunctional family that was to appear on The Tracey Ullman Show.

Besides The Simpsons, Cartwright has also voiced numerous other animated characters, including Daffney Gillfin in Snorks, Mellissa Screetch in Toonsylvania, Rufus in Kim Possible, Mindy in Animaniacs, Pistol in Goof Troop, the Robots in Crashbox, Margo Sherman in The Critic and Todd Daring in The Replacements.

While in the fourth grade at the school of St. Charles Borromeo, she won a school-wide speech competition with her performance of Rudyard Kipling's How the Camel Got His Hump.

She regularly entered public speaking competitions, placing first in the "Humorous Interpretation" category at the National District Tournament two years running.

[11] One of these was Daws Butler, known for voicing characters such as Huckleberry Hound, Snagglepuss, Elroy Jetson, Spike the Bulldog, and Yogi Bear.

At the end of 1980, Cartwright signed with a talent agency and landed a lead role in a pilot for a sitcom called In Trouble.

[18] During the summer, Cartwright worked with Jonathan Winters as part of an improvisation troupe at Kenyon College in Gambier, Ohio.

[17] Returning to Los Angeles, Cartwright won the lead role in the television film Marian Rose White.

Janet Maslin, a critic for The New York Times, described Cartwright as "a chubby, lumbering, slightly cross-eyed actress whose naturalness adds greatly to the film's impact".

[20] Later, Cartwright auditioned for the role of Ethel, a girl who becomes trapped in a cartoon world in the third segment of Twilight Zone: The Movie.

[22] Cartwright continued to do voice work for projects including Pound Puppies, Popeye and Son, Snorks, My Little Pony and Saturday Supercade.

[23] She joined a "loop group", and recorded vocals for characters in the background of films, although in most cases the sound was turned down so that very little of her voice was heard.

She did minor voice-over work for several films, including The Clan of the Cave Bear (1986), Silverado (1985), Sixteen Candles (1984), Back to the Future Part II, and The Color Purple (1985).

[24] Cartwright also voiced a shoe that was "dipped" in acid in Who Framed Roger Rabbit (1988), describing it as her first "off-screen death scene",[24] and worked to correctly convey the emotion involved.

He recommended that Cartwright study La Strada, a 1956 Italian film starring Giulietta Masina and directed by Federico Fellini.

She began performing "every imaginable scene" from La Strada in her class and spent several months trying to secure the rights to produce a stage adaptation.

Although they never met, Cartwright kept a journal of the trip and later wrote a one-woman play called In Search of Fellini, partially based on her voyage.

On March 13, 1987, she auditioned for a series of animated shorts about a dysfunctional family that was to appear on The Tracey Ullman Show, a sketch comedy program.

[32] However, she wanted to appear in the live-action sketches and occasionally showed up for recording sessions early, hoping to be noticed by a producer.

During the first season of The Simpsons, Fox ordered Cartwright not to give interviews, because they did not want to publicize the fact that Bart was voiced by a woman.

[39] Cartwright's normal speaking voice is said to have "no obvious traces of Bart",[25] and she believes her role is "the best acting job in the world"[25] since she is rarely recognized in public.

[25] Bart's catchphrase "Eat My Shorts" was an ad-lib by Cartwright in one of the original table readings, referring to an incident from her high school days.

[40] Cartwright voices several other characters on the show, including Nelson Muntz, Ralph Wiggum, Todd Flanders, Kearney, and Database.

In addition to her work on The Simpsons, Cartwright has voiced many other characters on several animated series, including Chuckie Finster in Rugrats and All Grown Up!, Margo Sherman in The Critic, Mindy in Animaniacs, and Rufus the naked mole-rat in Kim Possible.

"[56] Other television shows that have used her voice work include Galaxy High, God, the Devil and Bob, Goof Troop, Mike, Lu & Og, The Replacements, Pinky and the Brain and Timberwolf.

[58] Cartwright has appeared on camera in numerous television shows and films, including Fame, Empty Nest, The Fresh Prince of Bel-Air, Flesh and Blood, Godzilla, and 24.

[4] The play received modest reviews, including criticism for a lack of inside stories about The Simpsons, and its "overweeningly upbeat" tone.

[67] In 2016, Cartwright launched Spotted Cow Entertainment, her own film and television production company, with Peter Kjenaas, Monica Gil and Kevin Burke.

With a focus on international audiences, Spotted Cow is seeking "to finance, produce and acquire live action and animated films, television series, as well as entertainment for digital platforms with budgets up to $15M.