Travolta confirmed his wife's death in an Instagram post late Sunday. He said she died after a two-year battle with breast cancer.
"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," Travolta said of his wife of 28 years. "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 Center, all the medical centers that have helped, as well as her many friends and loved ones who have been by her side," he continued. "Kelly's love and life will always be remembered. I will be taking some time to be there for my children who have lost their mother, so forgive me in advance if you don't hear from us for a while. But please know that I will feel your outpouring of love in the weeks and months ahead as we heal. All my love, JT."
Preston and Travolta were married at a midnight ceremony in Paris in 1991 while the couple were expecting their first son, Jett.
In January 2009, Jett Travolta, 16, died after a seizure at the family's vacation home in the Bahamas. The death touched off a court case after an ambulance driver and his attorney were accused of trying to extort $25 million from the actors by threatening to release sensitive information about their son's death.