Martha Maria Yeardley Smith (/ˈjɑːrdli/ YARD-lee; born July 3, 1964) is an American actress. She stars as the voice of Lisa Simpson on the animated television series The Simpsons. Smith began acting in 1982 after graduating from drama school. She moved to New York City in 1984, where she appeared in the Broadway production of Tom Stoppard's The Real Thing.