With their father dead and their mother busy trying to land a steady beau, pretty teen Billy Jean Davy (Helen Slater) and her younger brother, Binx (Christian Slater), spend their time riding Binx's moped and dreaming of life in Vermont -- several climate zones away from the humid, omnipresent heat of their Texas town.
One day, on their way from their trailer park home to a swimming hole, the Davy kids run afoul of rich boy Hubie Pyatt (Barry Tubb) and his cronies, who steal -- and later trash -- the scooter Binx bought with his father's paltry life insurance benefits.
Demanding payment from Hubie and his merchant dad (Richard Bradford) for the damage that's been inflicted on both the bike and her brother's face, Billie Jean narrowly escapes being raped by the elder Pyatt.
In the ensuing scuffle, Binx accidentally shoots Mr. Pyatt, sending himself, Billie Jean, and their friends, Ophelia (Martha Gehman) and Putter (Yeardley Smith), on the lam.
When the Billie Jean Gang becomes a media sensation, Pyatt capitalizes on their notoriety by selling T-shirts and bric-a-brac, while policeman Ringwald (Peter Coyote), who feels guilty for having refused to help Billie Jean, tries to bring the kids in without anyone getting hurt.
However, when the gang mock-kidnaps rich amateur filmmaker Lloyd (Keith Gordon), unaware that he's the district attorney's son, the situation spins out of control.
Soon, Lloyd's videotape of the suddenly crop-topped, Joan of Arc-emulating, eminently telegenic Billie Jean elevates a local headline into a national sensation, and even Lloyd's attraction to Billie Jean can't protect her from the media lightning rod she's become.
The Legend of Billie Jean marks the screen debut of Christian Slater, who is no relation to co-star Helen Slater. Actor Gordon, who made his debut as a screenwriter with Mark Romanek's Static the year Billie Jean came out, would go on to direct a number of critically acclaimed films.