Martha Maria Yeardley Smith is an American actress best known for voicing Lisa Simpson on The Simpsons since its inception as a series of shorts on The Tracey Ullman Show. She is the only main cast member on the show who does not voice multiple characters. Prior to The Simpsons, she was a regular on the sitcom Brothers. She has also been a regular on Herman's Head and had recurring roles on Dharma & Greg, Dead Like Me, Phil of the Future and The Mindy Project. Her films include Heaven Help Us, Maximum Overdrive, City Slickers, Toys and As Good as It Gets.
- Heaven Help Us (1985): Kathleen.
- The Legend of Billie Jean (1985): Putter.
- Maximum Overdrive (1987): Connie.
- Brothers (1987-1989): Louella Waters.
- Mathnet (1987): Jane Rice-Burroughs.
- The Simpsons (1989-present): Lisa Simpson.
- The Simpsons Movie (2007): Lisa Simpson.
- City Slickers (1991): Nancy.
- Herman's Head (1991-1994): Louise Fitzer.
- Toys (1992): Miss Drum.
- We're Back! A Dinosaur's Story (1993): Cecilia Nuthatch.
- As Good as It Gets (1997): Jackie Simpson.
- Dharma & Greg (1997-2002): Marlene.
- Dead Like Me (2004): Penny.
- Phil of the Future (2005): Mandy Teslow.
- The Mindy Project (2014-2015): Carolyn.