Jenny O'Hara is part of a performing family whose influence encompasses regional and New York theater from Warren, PA, to Greenwich Village and Broadway, and rock music from England to New York. Born in Sonora, CA, her father, John B. O'Hara, was a salesman and her mother, Edith, a journalist and drama teacher. Jenny, her singer/actress younger sister Jill O'Hara, and her singer/guitarist brother Jack O'Hara, grew up amid their mother's pursuit of a theatrical career, leading a gypsy-like existence in half-built houses and other accouterments of a struggling existence. Edith O'Hara directed a children's theater in Warren, where the two daughters occasionally participated as actresses during their teens, though neither took it seriously. Jenny spent a year at Carnegie Tech and a summer playing in stock theater, and then came to New York to study with Lee Strasberg and Sanford Meisner. She was in touring companies of Cactus Flower and Brecht on Brecht, with Lotte Lenya; off-Broadway productions of Arms and the Man, Play With the Tiger, and Hang Down Your Head and Die; and stock productions of Paint Your Wagon and Take Me Along, among many other musicals and straight plays. She also appeared on ABC's Time for Us. O'Hara's biggest stage credit of the '60s was in Dylan (opposite Alec Guinness) as Annabelle Graham-Pike. In 1970, O'Hara succeeded her younger sister Jill in the musical Promises, Promises. By the mid-'70s, Edith O'Hara was running the 13th Street Theatre in Greenwich Village (a major venue for off-off-Broadway and children's theater), and her brother Jack was in London, playing guitar and bass and singing with the band Eggs Over Easy, pioneering the pub rock scene in England. Meanwhile, Jenny had graduated to television, both in series and made-for-TV features, including a starring role in Brink's: The Great Robbery, The Return of the World's Greatest Detective (in which she took over a role originated by Joanne Woodward in the movie They Might Be Giants), Blind Ambition, and Blinded by the Light. She later worked in movies such as Career Opportunities, Mystic River, and Matchstick Men, and television series such as Law & Order, NYPD Blue, and ER.