June Lockhart, widely recognized for her roles as an American mother figure in two notable television series, passed away on Thursday, October 23, 2025, at her residence in Santa Monica, California, due to natural causes. She was 100 years old.
Lockhart passed away at 9:20 p.m. local time with her daughter, June Elizabeth, and granddaughter, Christianna, present. Famous for her roles as Ruth Martin on “Lassie” and Dr. Maureen Robinson on “Lost in Space,” she was among the last actors from Hollywood’s Golden Age.
Born on June 25, 1925, in New York City, Lockhart was the only child of actors Gene and Kathleen Lockhart. Her father, a founding member of the Screen Actors Guild, was nominated for an Oscar in 1939 for his role in Algiers and appeared in films such as “His Girl Friday,” “Abe Lincoln in Illinois,” and “Miracle on 34th Street.” Her parents met through Thomas Edison, as they traveled demonstrating his phonograph invention.
Lockhart’s career in entertainment began at the age of eight, when she appeared in a pantomime scene in Peter Ibbetson at the Metropolitan Opera House in New York, where she studied ballet. She made her film debut at the age of 13 in MGM’s 1938 adaptation of “A Christmas Carol,” appearing alongside her parents as Belinda Cratchit. Before reaching 25, she appeared in “All This and Heaven Too” with Charles Boyer and Bette Davis, as Gary Cooper’s sister in “Sergeant York,” and as Lucille Ballard in “Meet Me in St. Louis.”
Her Broadway debut in 1947 in the comedy “For Love or Money” made her an overnight sensation. She received a Tony Award for an exceptional debut performance, along with the Donaldson Award and the Theater World Award. The Associated Press named her Drama’s Woman of the Year.
Lockhart gained television fame when she replaced Cloris Leachman as Ruth Martin on “Lassie” in September 1958. Initially turning down the role, she reconsidered and portrayed the farm wife for over 200 episodes, receiving an Emmy nomination in 1959. Her co-stars included Hugh Reilly and Jon Provost, with four different dogs playing the famous collie.
Provost, now 75, shared his memories on social media after learning of Lockhart’s death. “June and I worked together on “Lassie” from 1958 to 1964, she truly was my second mother,” Provost wrote. He recalled the advice she gave him about professionalism on set and noted that they stayed in touch over the years.
After the family was written out of “Lassie” in 1964, Lockhart transitioned to “Lost in Space” in 1965 as Maureen Robinson. The series ran until 1968 and featured the Robinson family stranded in space.
Bill Mumy, who played her son Will Robinson, remembered Lockhart as brilliant and nurturing. He described her as talented and adventurous, emphasizing her enjoyment of her role in “Lost in Space,” which she described as her favorite project.
Following “Lost in Space,” Lockhart joined “Petticoat Junction” during its sixth season as Dr. Janet Craig, remaining with the show until it ended in 1970.
Her career continued into her later years with roles on “General Hospital” and “Beverly Hills 90210,” and guest appearances on shows like “The Beverly Hillbillies,” “Happy Days,” “Full House,” “Roseanne,” and “Grey’s Anatomy.” She received two stars on the Hollywood Walk of Fame, one for motion pictures and one for television.
Lockhart was an advocate for NASA, appearing with astronauts Neil Armstrong and Buzz Aldrin when NASA Television won a primetime Emmy Award in 2009. Her daughter, June Elizabeth, noted her mother’s true passions were journalism, politics, science, and NASA, and that she inspired many future astronauts.
Lockhart was also a supporter of animal rights, backing the Santa Monica Mounted Police Horses and serving as a spokesperson for International Hearing Dog, Inc. Her family noted her affection for her grand-pug, Massimo.
