June Lockhart, the actress who starred in Lost in Space and Lassie, died on Thursday, October 23, 2025, of natural causes. According to a spokesperson, she died at home surrounded by family. She was 100 years old.

Lockhart had an acting career that spanned over 80 years. She started out in the golden age of Hollywood, played the mother roles in beloved series like Lassie and Lost in Space, and continued acting throughout her lifetime, with a recent role in 2021.

She was born on June 25, 1925, in New York City to actors Gene and Kathleen Lockhart. She made her film debut in 1938, opposite her parents in A Christmas Carol. The young actress had roles in All This, and Heaven Too, Sergeant York, Meet Me in St. Louis, Son of Lassie, She-Wolf of London, and The Yearling. She started working more in television in the ‘50s, appearing in Justice, Appointment with Adventure, Gunsmoke, Have Gun – Will Travel, Rawhide, and Wagon Train.

From 1958 to 1964, Lockhart starred in the wholesome family show Lassie as Ruth Martin, the mother to adventures young Timmy. After leaving the show, she appeared in Perry Mason, Bewitched, The Man from U.N.C.L.E., The Alfred Hitchcock Hour, and The Red Skelton Hour.

Then she played matriarch Maureen Robinson in the popular sci-fi family show Lost in Space, which ran for three seasons from 1965 to 1968. Lockhart’s next starring TV role was as Dr. Janet Craig in the sitcom Petticoat Junction from ’68 to ’70.

Continuing to work in television, she did episodes of Love, American Style, Adam-12, Police Story, Happy Days, Magnum, P.I., and Falcon Crest. Lockhart was in Deadly Games, Knots Landing, The Greatest American Hero, Troll, The New Lassie, and had a recurring role in General Hospital that went from ’84 to ’98.

Then she was in Full House, Babylon 5, Roseanne, Step by Step, 7th Heaven, and Beverly Hills, 90210. Throughout the 2000s and 2010s, Lockhart was in One Night at McCool’s, The Drew Carey Show, Grey’s Anatomy, and Cold Case. Her final role was voicing Alpha Control in the most recent Lost in Space series in 2021.