Olivia Newton-John has died, her family has confirmed.
In a post to the Grease star's Facebook page, her husband John Easterling praised her for being a 'symbol of triumphs and hope'.
He also asked people to give the family some privacy at this difficult time.
Mr Easterling said: "Dame Olivia Newton-John (73) passed away peacefully at her Ranch in Southern California this morning, surrounded by family and friends.
"We ask that everyone please respect the family’s privacy during this very difficult time.
"Olivia has been a symbol of triumphs and hope for over 30 years sharing her journey with breast cancer.
"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 lieu of flowers, the family asks that any donations be made in her memory to the Olivia Newton-John Foundation Fund (ONJFoundationFund.org).
"Olivia is survived by her husband John Easterling; daughter Chloe Lattanzi; sister Sarah Newton-John; brother Toby Newton-John; nieces and nephews Tottie, Fiona and Brett Goldsmith; Emerson, Charlie, Zac, Jeremy, Randall, and Pierz Newton-John; Jude Newton-Stock, Layla Lee; Kira and Tasha Edelstein; and Brin and Valerie Hall."
Newton-John made her name in the 1978 high school classic Grease, where she starred as Sandy opposite John Travolta's Danny.
The musical catapulted her into superstardom, gaining an army of fans around the world.
In recent years, the Australian actor had been very open about her breast cancer diagnosis, which she received in 1992.
Throughout her diagnosis, she underwent numerous treatments, including a mastectomy, chemotherapy and breast reconstruction.
Since news of her death was announced, many of the singer's fans have taken to social media to offer their condolences to her family.
One said: "This one hurts deeply. My inner 11 year self is shattered. Farewell Olivia Newton-John."
Echoing the shock, another commented: "Rest In Peace Olivia Newton-John. Fly high in Greased Lightning."
"RIP Olivia Newton-John - a generation of '70s kids will never forget you," put a third.
While another added: "Grease is a movie I’ll never get enough of. Those black leggings, that blonde curly hair, that incredible voice that I tried to imitate as child in front of mirror. RIP Dame Olivia Newton-John who has died at age of 73."