Cartwright has also appeared in live action, including Joe Dante's segment of Twilight Zone: The Movie and the Made-for-TV Movie Marian Rose White, and the American Godzilla movie (which also had Hank Azaria and Harry Shearer of The Simpsons), as well as making a guest appearance on an episode of 24 (the same season, stars Kiefer Sutherland and Mary Lynn Rajskub returned the favor by reprising their roles on 24 for a guest appearance on The Simpsons). Originally, she was going to do voicework on South Park, but turned it down due to its vulgar content. She even was a celebrity guest on Tom Bergeron's The Hollywood Squares and Donny Osmond's Pyramid.
Outside show business, Cartwright is a prominent member of the Church of Scientology.
Cartwright has done character voices for the following works:
- Richie Rich (Hanna-Barbera's version, as Gloria)
- Shirt Tales (season 2 only, as Kip Kangaroo)
- The Snorks
- Popeye and Son
- Saturday Supercade (season 2 only, in "Space Ace" segments)
- Galaxy High
- Animaniacs (Mindy, additional voices)
- The Simpsons (Bart Simpson, Ralph Wiggum, Nelson Muntz, Kearney [the bully who looks like a teenager, but isn't], Todd Flanders, and any one-shot boy characters. Cartwright also provides vocal effects [mostly cooing, laughing and crying] for Maggie Simpson and was the replacement voice for Elizabeth Taylor when the season 13 episode of The Simpsons showed a clip from season 4's "Lisa's First Word", where Maggie finally says her first word "Daddy" after Homer wishes that she never speak)
- Rugrats (Chuckie season 8 onward)
- Goof Troop (Pistol Pete)
- The Critic (Margo Sherman, various)
- Kim Possible (Rufus)
- The Replacements (Todd Daring)
- Mike, Lu & Og (Princess Lu)
- Putt-Putt (Enters the Race, Joins the Circus, and One-Stop Fun Shop only, as Putt-Putt)
- My Little Pony: The Movie and My Little Pony 'n Friends: Gusty the unicorn, Posey the earth pony.
- Pound Puppies (1980s): Bright Eyes
- Bonkers: Fawn Deer.
- Toonsylvania: Melissa Screetch
- Fantastic Max: FX.