American stage and screen actor who enjoyed huge success on the television shows Lassie and Lost in Space

June Lockhart, who has died aged 100, started her career in films, but made her name after switching almost exclusively to television. Having been given little chance to scintillate in the movies from her debut as a child in 1938 until 1947, she shone on the small screen in scores of popular series, above all in Lassie.

Taking over from Cloris Leachman in 1958, Lockhart continued in the show until 1964. She played Ruth Martin, married to the farmer Paul Martin (Hugh Reilly), and the adoptive mother of seven-year-old Timmy Martin (Jon Provost), whose collie was the titular hero of the series.

In her role as a housewife, Lockhart somehow managed to avoid being completely upstaged by the clever canine. She described the show as “a fairy tale about people on a farm in which the dog solves all the problems in 22 minutes, in time for the last commercial”. After she left the show, Lockhart commented: “In six sexless years of playing a country wife and mother, I was hardly ever allowed to kiss Hugh Reilly on the cheek.”

Lockhart went straight into another hit, Lost in Space (1965-68), a semi-spoof sci-fi series aimed mostly at children and inspired by The Swiss Family Robinson, the 19th-century novel by Johann David Wyss. Lockhart and Guy Williams portrayed Maureen and John Robinson, two scientists exploring alien planets. Lockhart had to spend most of her time deftly trying to survive special effects. As the series continued, the narrative became less and less about this Swiss Family Robertson in space and more about the Robertsons’ young son (Billy Mumy) and his friendship with a robot, and the cowardly villain Dr Zachary Smith (Jonathan Harris).