Martha Maria Yeardley Smith (/ˈjɑːrdli/ YARD-lee; born July 3, 1964) is an American actress. She voices 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. She made her film debut in 1985's Heaven Help Us, followed by roles in The Legend of Billie Jean and Maximum Overdrive. She moved to Los Angeles in 1986 an...