Plimpton was born November 16, 1970 in New York City, the daughter of actors Keith Carradine and Shelley Plimpton. Her paternal grandfather was actor John Carradine and she is the niece of Robert and the late David Carradine.

She first appeared as Jonsy in the feature film The River Rat (1984) before rising to prominence in the Richard Donner film The Goonies (1985) portraying the character Stef.

Martha Plimpton's Family Tree