Nancy Cartwright (born October 25, 1957)[1] is an American actress. She is the long-time voice of Bart Simpson on the animated television series The Simpsons, for which she has received a Primetime Emmy Award for Outstanding Voice-Over Performance and an Annie Award for Best Voice Acting in the Field of Animation. Cartwright also voices other characters for the show, including Nelson Muntz, Ralph Wiggum, Todd Flanders, Kearney, Database, and Maggie.

Cartwright was born in Dayton, Ohio. She moved to Hollywood in 1978 and trained alongside voice actor Daws Butler. Her first professional role was voicing Gloria in the animated series Richie Rich, which she followed with a starring role in the television movie Marian Rose White (1982) and her first feature film, Twilight Zone: The Movie (1983). 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. Cartwright intended to audition for the role of Lisa Simpson, the middle child; when she arrived at the audition, she found the role of Bart—Lisa's brother—to be more interesting. Matt Groening, the series' creator, allowed her to audition for Bart and offered her the role on the spot. She voiced Bart for three seasons on The Tracey Ullman Show, and in 1989, the shorts were spun off into a half-hour show called The Simpsons.

Besides The Simpsons, Cartwright has also voiced numerous other animated characters, including Daffney Gillfin in Snorks, Rufus in Kim Possible, Mindy in Animaniacs, Pistol in Goof Troop, the Robots in Crashbox, Margo Sherman in The Critic, Todd Daring in The Replacements, and Charles "Chuckie" Finster in Rugrats and All Grown Up! (a role she assumed in 2002, following the retirement of Christine Cavanaugh). In 2000, she published her autobiography, My Life as a 10-Year-Old Boy, and four years later, adapted it into a one-woman play. In 2017, she wrote and produced the film In Search of Fellini.