“My dearest Olivia, you made all of our lives so much better,” the actor wrote on Instagram. “Your impact was incredible. I love you so much.”
Newton-John and Travolta gained international fame when in 1978 when they starred as bad boy Danny and sweet Sandy in the movie musical “Grease.”
Just a few years ago, the pair revisited their roles for one special night in West Palm Beach, Florida when they attended a sing-along of the movie and a Q&A session at the Coral Sky Amphitheatre.
Newton-John wore her signature yellow skirt and matching cardigan, complete with the white button up. Travolta wore a classic leather jacket, with his hair slicked back.
It was the first time the two had been in costume since they first made the movie more than 40 years ago, Newton-John wrote on Instagram at the time.
In his tribute, Travolta added, “We will see you down the road and we will all be together again.”
He signed it: “Yours from the moment I saw you and forever! Your Danny, your John.”