Trivia

Originally read for the role of "Bart" when auditioning for The Simpsons (1989), but her voice was too high and sounded like a girl, so she lightened her voice up a little and then auditioned and won the role of "Lisa". Nancy Cartwright had originally read for "Lisa", but was given the role of "Bart" instead.

Is only one of two actresses (the other being Marcia Wallace) on The Simpsons (1989) to regularly play only one character. Most of the other actors play ten or more characters, while Julie Kavner plays four characters and Phil Hartman played two characters.

Her father, J.Y. Smith, who died in 2006, was a longtime obituary writer for The Washington Post.

Her forename is pronounced "Yard-lee".

Of the core 6 The Simpsons performers, Yeardley is the youngest.

Played the droid character EV-9D9 (major domo of Jabba's droids) in the NPR radio dramatization of Star Wars: Episode VI - Return of the Jedi (1983) [1996].

She was considered for the role of Serleena in Men in Black II (2002), but the role went to Lara Flynn Boyle.

Doing a one woman show in New York at the Union Square Theatre (April 2004)

Starring in Balancing Act at the Falcon Theatre in Burbank, California. (April 2007)

She is a lifelong Democrat.

Is exactly 5 years the senior of Shawnee Smith ("The Blob", "Saw"), and exactly 21 years the junior of Kurtwood Smith ("Robocop", "That 70's Show"). None of the Smiths are related, however.