She died due to breast and bone cancer, according to Radar Online, which reported that she was laid to rest at Pierce Brothers Westwood Village Memorial Park & Mortuary.
Locke had a contentious relationship of more than a decade with Clint Eastwood, who first cast her in “The Outlaw Josey Wales.”
Locke was born in 1944 as Sandra Louise Smith and raised in Shelbyville, Tenn. She changed her named to Sondra in her early 20s and won a nationwide talent search in 1967 for the part of teenager Mick Kelly in the movie adaptation of Carson McCullers’ novel “The Heart Is a Lonely Hunter.” Locke starred opposite Alan Arkin, who was nominated for a Best Actor Oscar. She also received Golden Globe nominations for Best Supporting Actress and Most Promising Newcomer.
Locke then starred in “Cover Me Babe,” “Willard,” “A Reflection of Fear,” and “The Second Coming of Suzanne” and took TV roles in “The F.B.I.,” “Cannon,” “Barnaby Jones,” “Kung Fu,” “A Feast of Blood” and “Gondola.” She started working with Eastwood in “The Outlaw Josey Wales” in 1976, followed by “The Gauntlet,” “Every Which Way But Loose,” “Any Which Way You Can,” “Bronco Billy” and “Sudden Impact,” in which she murders the men who had raped her and her sister.
Turning to directing, she helmed 1986’s “Ratboy,” 1990’s “Impulse,” 1995’s TV movie “Death in Small Doses” and the independent film “Do Me a Favor,” starring Rosanna Arquette.
She sued Eastwood for palimony in 1989 and for fraud in 1995 and brought a separate action against Warner Bros. for allegedly conspiring with Eastwood to sabotage her directorial career. She settled the three cases out of court.
Locke underwent a double mastectomy in 1990. Her autobiography “The Good, the Bad, and the Very Ugly – A Hollywood Journey,” was published in 1997.
Locke starred recently with Keith Carradine in Alan Rudolph’s drama “Ray Meets Helen.”
She is survived by her husband Gordon Anderson.