'LOVE AT FIRST SIGHT'
Travolta, who rose to fame in the late 1970s thanks to box office smash hits Saturday Night Fever and Grease, was a Hollywood star when he first locked eyes with Preston.
The pair met at a screen test in 1987 for the movie comedy The Experts, in which they both starred, when Preston was married to fellow actor Kevin Gage.
Appearing on Watch What Happens Live With Andy Cohen in 2018, Preston revealed Travolta felt it was "love at first sight".
On whether she fell in love too, her answer was: "Kinda" with a laugh, given she was married at the time.
"I was not that happily married let's put it that way. I was really with the wrong person," she said.
After divorcing Gage in 1987, Preston wasn't quite ready for a serious relationship with a smitten Travolta. She went on to date fellow Hollywood icons George Clooney and Charlie Sheen, before settling down with Travolta.
The couple dated for four years before Travolta proposed to Preston while they were holidaying in Switzerland in 1990.
They were married in France in 1991.
When asked about the secret to their long-lasting marriage in a joint 2017 interview, Travolta said the couple stayed in touch with one another.
"We really care deeply about each other and we protect each other — and we keep (our relationship) up to date," Travolta told Closer Weekly in a recent interview.
"Keep checking in and keep growing and changing. Keep doing things, just the two of you," Preston added.
The pair appeared together in Preston's final film role in the 2018 film Gotti, in which she played Victoria Gotti, the wife of Mafia boss John Gotti, who was portrayed by Travolta.
SHOCK DEATH OF SON
Their story was one of enduring love but the pair suffered immeasurable tragedy with the death of their 16-year-old son Jett, who died in 2009 after suffering a seizure at his family's vacation home in the Bahamas.
"It's the worst thing that's ever happened in my life," Travolta told Us Weekly in January last year. "The truth is, I didn't know if I was going to make it."
A house caretaker found Jett unconscious in a bathroom after hitting his head. He was taken by ambulance to a local hospital, where he was pronounced dead.
The teen, who was the oldest child of Travolta and Preston, had a history of seizures.
In 2003, Preston told Montel Williams that when Jett was two years old he became very ill before being diagnosed with Kawasaki disease, a condition that can cause inflammation of the arteries.
Travolta credited the Church of Scientology for helping him cope with the family tragedy.
"The church never left our side for two years," said Travolta. "I don't know if I would have made it through without their support."
MOVING TRIBUTE
Travolta paid tribute to his wife in a heartbreaking Instagram post.
"It is with a very heavy heart that I inform you that my beautiful wife Kelly has lost her two-year battle with breast cancer," he posted.
"She fought a courageous fight with the love and support of so many. My family and I will forever be grateful to her doctors and nurses at MD Anderson Cancer Centre, all the medical centres that have helped, as well as her many friends and loved ones who have been by her side. Kelly's love and life will always be remembered."