Newton-John is best-known for starring in the 1978 musical "Grease" alongside Travolta, as the-girl-next-door Sandy, who trades her ankle-length skirt and prim and proper hair for skin-tight black pants and a perm.
The high school sweetheart-turned-bad girl resonated with audiences worldwide, and continues to capture hearts decades after the movie was released.
"Making it was fun but you never know with movies if audiences are going to go with it or not, even if you love it," she said in a Forbes interview in 2018.
"It is incredible that it is still going but it's not even just that, it's showing no signs of stopping. You say 'Sandy and Danny' and people instantly know what you're talking about."
"Grease" remained the highest-grossing musical for three decades, with Newton-John and Travolta maintaining a close relationship long after the film was made.
"She was my favorite thing about doing Grease," Travolta said in an interview to mark the film's 40 anniversary in 2018.
There was no one else "in the universe" who could play Sandy, he said of Newton-John, who turned 29 during the making of Grease and later revealed she had to be convinced by Travolta to take up the role after self-doubts that she was too old to play a teenager.
"If you were a young man in the '70s..., if you remember that album cover with Olivia with that blue shirt on, with those big blue eyes staring at you," Travolta recalled.
"Every boy's, every man's dream was: 'Oh, I would love for that girl to be my girlfriend'." -- With AFP
