Born in the vibrant city of New York, Penelope Windust was the daughter of renowned French-born stage and screen director Bretaigne Windust, who was born in 1906 and passed away in 1960, and his talented actress wife Irene, who was born in 1921 and passed away in 1999. Penelope went on to complete her drama training at Pittsburgh's prestigious Carnegie Tech, which later became Carnegie Mellon University. She made her Broadway debut in 1967 at the American National Theatre in Herman Shumlin's play Spofford, which was based on the novel Reuben, Reuben and was subsequently filmed, starring the talented Tom Conti. In 1972, Penelope took on the title role of Elizabeth I at the Lyceum Theatre, earning a Tony Award nomination and offering a season at the Old Globe in San Diego. Her impressive theatrical credits also included roles in The Elephant Man and The Lion in Winter at the South Coast Repertory Theatre in 1983 and appearances at the Mark Taper Forum in Los Angeles.
As a relatively latecomer to the screen in 1975, Penelope primarily worked in episodic television as a supporting actress. She is perhaps best remembered for her role as botanist Kathleen Maxwell, who joins the Resistance in the original science fiction miniseries V in 1983. Her extensive gallery of characters has included a diverse range of murder suspects, murder victims, and assorted doctors/scientists in various television shows such as Mannix, Ellery Queen, Matlock, Nero Wolfe, Criminal Minds, Hawaii Five-O, The Six Million Dollar Man, Wonder Woman, and Falcon Crest. In one of her rare motion picture appearances, she played a saloon proprietress in the 1988 film Ghost Town.
Penelope Windust was married to actor Charles Haid from 1969 to 1984, with whom she had two daughters.