After all, the movie musical was what sparked his decades-long friendship with Olivia Newton-John, he told E! News in 2018 while attending a celebration for the 40th anniversary of Grease with his co-star. When asked about his favorite memory from the making of the 1978 film, the actor said "beyond the shadow of a doubt" that it was meeting Newton-John.
"I have to say the same," Newton-John said at the time, explaining that Travolta was the one who "talked me into" taking the role of Sandy Olsson to his Danny Zuko. "That was a magical, magical day."
And though the two each starred in dozens of projects since that fateful meeting, they still found time in their busy schedules to catch up with each other over the years. As Travolta noted, they often saw one another "two to three times a year."
"More than that," he added, "it's texting and emails."
Almost four years after that interview, Newton-John passed away on Aug. 8 at the age of 73. In a statement posted to her social media accounts, the actress' husband, John Easterling, shared that she died at her Southern California ranch while surrounded by friends and family.
"Olivia has been a symbol of triumphs and hope for over 30 years sharing her journey with breast cancer," he wrote. "Her healing inspiration and pioneering experience with plant medicine continues with the Olivia Newton-John Foundation Fund, dedicated to researching plant medicine and cancer."
In the wake of Newton-John's death, Travolta, 68, penned a heartfelt tribute to his "dearest" friend and shared how she "made all of our lives so much better."
"Your impact was incredible. I love you so much," he wrote in an Instagram post addressed to the late star. "We will see you down the road and we will all be together again. Yours from the first moment I saw you and forever!"
He added in his signoff, "Your Danny, your John!"
For more tributes from the cast of Grease, click here.