She cemented herself as one of the world's most celebrated stars, thanks to her powerful voice and leading roles in beloved films like Grease, but these days it's Olivia Newton-John's brave fighting spirit that she's most admired for.
Olivia, 71, has remained positive and optimistic about her almost three-decade-long cancer battle, but she's no stranger to heartache. Behind the scenes, she's bravely harboured a 28-year family secret that changed the course of her life.
In 1991 Olivia, then married to her Xanadu co-star Matt Lattanzi, suffered the loss of her beloved five-year-old goddaughter Colette Chuda from cancer.
The daughter of one of Olivia's closest friends Nancy Chuda, the little girl passed away from Wilms tumour, a rare form of kidney cancer, leaving both families devastated.
"My hands shook and I couldn't stop crying," Olivia revealed in her 2018 memoir Don't Stop Believin'. "How could we live without our Colette? My heart took a long time to mend," she said.
Earlier this month, Olivia's daughter Chloe Lattanzi, who she shares with her ex-husband Matt, opened up about the tragedy.
"My best friend dying of cancer when we were both five had me thinking about mortality at a very young age," revealed the 34-year-old.
"This created many fears in me, but it also created a sensitive, thoughtful little girl curious about the nature of the universe."
As if the death of her closest friend wasn't hard enough, Chloe revealed she discovered her own mother's cancer diagnosis at the hands of a schoolyard bully around the same time.
"Some little brat ran up to me and said, 'Ha ha, your mum's got cancer and she's going to die.' It's like a screenshot in my head I'll never forget. I went home and said to my mum, 'Why didn't you tell me? I could've taken care of you!"
Olivia was first diagnosed with breast cancer in 1992, and while she went into remission after eight months of treatment, the illness returned in 2013, then a third time in 2017, where it was classified as stage four.
WATCH BELOW: Olivia Newton-John opens up about her cancer battle. Post continues after video...
The singer has had plenty of testing times, including the disappearance of her former partner Patrick McDermott in 2005 – but last week she had fans captivated when she made a rare appearance Down Under!
Holding back tears after watching Chloe wow the judges on Dancing With The Stars, she was overwhelmed with emotion.
"I'm so proud and my heart is beating so fast and I'm trying not to cry," she gushed, telling Chloe she "did a wonderful job, just gorgeous".
In 2018, Chloe had fans wondering if she'd wed in secret when she added "wife to James Driskill" to her Instagram page. Now, the duo, who got engaged in 2010, are planning to adopt a baby!
"It's something they'd love to do sooner rather than later," reveals a source.
"ONJ's made no secret she wants grandkids, too!" Olivia revealed that in 1990 she, too, had wanted to adopt a child after multiple miscarriages.