Nancy Jean Cartwright is an American voice actress, film and television actress, and comedienne. She is known for her longrunning role as Bart Simpson on the animated television series The Simpsons. Cartwright also voices other characters for the show, including Nelson Muntz, Ralph Wiggum, Todd Flanders, Kearney, and Database.
Cartwright was born in Dayton, Ohio. Cartwright 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 and her first feature film, Twilight Zone The Movie .
Source: Wikipedia