Tributes have started to flow for Olivia Newton-John after it was announced this morning she lost her battle with cancer.
The 73-year-old actress had been battling with breast cancer for three decades, having previously beaten the illness twice.
Her husband John Easterling took to Facebook this morning to announce the heartbreaking news and now friends and family of the star have started sharing heartfelt tributes to their social media accounts.
Newton-John's daughter, Chloe Lattanzi, took to her official Instagram account to share a series of photos with her mother in the wake of her death.
Three days ago she also shared a heartfelt photo with her mum, calling the Aussie star her "best friend".
While her Grease co-star John Travolta issued a touching tribute on his Instagram account, "My dearest Olivia, you made all of our lives so much better. Your impact was incredible. I love you so much.
"We will see you down the road and we will all be together again. Yours from the moment I saw you and forever! Your Danny, your John!"
Australian singer-songwriter Kylie Minogue also praised the actress and said ever since she was 10 years old, she has looked up to the Grease star.
Sir Rod Stewart tweeted a goodbye to his "great friend" who he said "was the perfect Lady, gorgeous, with great poise and with a certain Aussie sophistication."
Internationally renowned cook, author, and TV personality Nigella Lawson took to Twitter with a simple but sweet tribute where she called Newton-John's memory a "blessing".
Meanwhile the outspoken talk show host Piers Morgan issued his own heartfelt tribute on his Twitter account, "So sad to hear the fabulously gutsy, warm & talented Olivia Newton-John has died."
Adding, "At an auction of her Grease memorabilia in LA three years ago, she told me her favourite song from the movie was Hopelessly Devoted To You. Great song, great film, great lady. RIP."
And fellow icon Barbra Streisand wrote on Instagram, "Too young to leave this world. May she RIP".
American comedian Dane Cook took to Twitter to thank the star for her "wonderful music and fun memories."
Spanish actor Antonio Banderas sent his "deepest condolences to her family and loved ones."
Australian-American musician Rick Springfield tweeted a heartfelt message to his long-time friend, saying, "the world is out of balance when we lose these magnificent people."
The Nanny star Fran Drescher took to Instagram to share a photo with her "sweet wonderfully talented" friend.
Bravo host Andy Cohen also took to Instagram to honour Newton-John.
He posted a video with the caption, "Hopelessly Devoted to YOU, Olivia Newton-John. Rest In Peace, Queen. Thank you for the music."
The Academy paid tribute to the beloved actress by posting a photo of Newton-John and Travolta at the 1978 Academy Awards.
They wrote, "Olivia Newton-John and John Travolta at the 50th Academy Awards (April 3, 1978).
"A few months later, they took the world by storm as Sandy and Danny in 'Grease' - which went on to become the highest grossing film of 1978, proving that Grease is (and forever will be) the word."
Award winning actress Viola Davis took to Twitter to express her gratitude for the iconic actress, "Oh man!!! You were my childhood!! Your talent, poise, beauty!! Rest in glorious peace. God bless your family....and thank you for creating eternal memories. "
Star Trek actor, George Takei, took to Twitter to share his tribute to Newton-John, praising her as a "great, iconic artist".
Actress Julianne Hough who starred in the 2016 Grease Live! show as Sandy took to Instagram to praise the "icon and legend".
Meanwhile, Australia's Nine Network US correspondent, Alison Piotrowski has reported that fans are gathering at Newton-John's star on the Hollywood Walk of Fame.
From 1973-83, Newton-John was among the world's most popular entertainers.
She had 14 top 10 singles just in the US, won four Grammys, starred with Travolta in Grease and with Gene Kelly in Xanadu. The fast-stepping Travolta-Newton-John duet, You're the One That I Want, was one of the era's biggest songs and has sold more than 15 million copies.