Nancy Jean Cartwright (born on October 25, 1957 in Dayton, Ohio) is an American actress, voice actress, comedian, clown, jester, mime and tap dance. She is known for providing the voices of Bart Simpson, Nelson Muntz, Todd Flanders and Ralph Wiggum on the animated television show "The Simpsons". She also plays the voice of Chuckie Finster on "Rugrats" and "All Grown Up!".