The British-born, Melbourne-raised performer died peacefully in her sleep at her home in California, according to a social media post from husband John Easterling.

The singer and actress, who is best known for her role alongside John Travolta in the smash movie musical Grease, had endured a recurring battle with breast cancer.

Travolta was among the first to pay tribute to his former co-star, posting on Instagram: “My dearest Olivia, you made all of our lives so much better. Your impact was incredible. I love you so much.”

However the impact of Newton-John’s passing also hit hard among her Australian fans and peers on Tuesday.

Kylie Minogue, whose career path followed that of Newton-John with her elevation to international fame from humble beginnings in Melbourne, said on Twitter: “Since I was 10 years old, I have loved and looked up to Olivia Newton-John. And, I always will.

“She was, and always will be, an inspiration to me in so many, many ways.”

Singer Delta Goodrem, who played Newton-John in a 2018 biopic, wrote on Instagram that the star was both a mentor and friend.

“The whole world will feel this heartbreak today because the entire world felt Olivia’s unmatched light,” she said.

“I don’t have all the words I would like to say today, but I hope everyone will join in celebrating our beloved Olivia, her heart, soul, talent, courage, grace … I love you forever.”

Deputy Prime Minister Richard Marles told ABC radio it was a “really sad day for Australia”.

“I think for people of my generation who grew up with Grease, it’s one of these moments where you feel like an era has come to an end and the world is a little emptier,” he said.

Debbie Sheill, director of the Olivia Newton-John Cancer Research Centre in Melbourne, said it was an especially sad day for everyone involved in the facility.

“It is because of her that the centre is here,” she told ABC TV.

“This was her dream and this was her legacy, and … something she was really proud of.”

Former prime ministers Kevin Rudd and Malcolm Turnbull both paid tribute to Olivia-Newton on Twitter.

“A great Australian woman. And a great advocate for global cancer research,” Rudd wrote, while Turnbull thanked the entertainer for her remarkable life.

“You lit up our lives with music and dance and you saved so many lives with your passionate … advocacy for cancer research and treatment,” he said.

Victorian premier Daniel Andrews said Newton-John’s generosity had saved lives and her advocacy had given people hope.

Newton-John was admitted to the Australian Recording Industry Association Hall of Fame in 2002 and made a Companion of the Order of Australia in 2019.

Veteran Seven Network entertainment report Peter Ford described her death as Australia’s “Princess Diana moment”

The British-born singer died “peacefully” at her ranch in Southern California on Monday morning, surrounded by family and friends.

Newton-John is best known for her starring role in the 1978 film Grease, in which she starred opposite John Travolta as Sandy.

Her performance saw her nominated for multiple awards including two Golden Globes, and various other film accolades.

She is also a multi-platinum selling singer, with two singles and two albums having earned the stamp from the Recording Industry Association of America.

Newton-John battled and defeated breast cancer in 1992 before its reappearance in 2013.

She was honoured with the star on the Hollywood Walk of Fame almost 41 years ago to the day of her death, on August 5, 1981.

Writing on Instagram, Travolta said her “impact was incredible” and signed off his tribute as “your Danny”.

“My dearest Olivia, you made all of our lives so much better,” he wrote.

“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 first moment I saw you and forever! Your Danny, your John!”

The soundtrack to Grease is one of the world’s best-selling albums of recorded music and features the two hit duets from Newton-John and Travolta: Summer Nights and You’re The One That I Want.

Newton-John was born on September 26, 1948, in Cambridge, England, where her father Bryn had been working on the Enigma project at Bletchley Park during WWII.

When she was six years old her family emigrated to Melbourne, where she attended Christ Church Grammar School and University High School.

After winning a trip to the UK on a TV talent show, Newton-John decided to try her luck in Great Britain where she recorded and released her first single for Decca in 1966.

International success eluded her until her first solo album in 1971, when the singles If Not For You and Banks of the Ohio charted around the world.

That began a string of hits including Let Me Be There, her signature tune I Honestly Love You, and 1981’s Physical which topped the US charts for 10 consecutive weeks.

During her life Newton-John received four Grammy Awards, an Emmy Award, numerous Country Music Awards, American Music Awards and People’s Choice Awards.

Her acting career took off in 1978, when the world fell in love with her as the sweet Sandy Olsson in the movie musical Grease alongside John Travolta, and two years later she danced with screen legend Gene Kelly in Xanadu.

The singer kept her head high through the mysterious disappearance of her boyfriend of nine years, Patrick McDermott, who was thought to have drowned off the coast of California in 2005 until evidence emerged in 2009 suggesting he had faked his death and was hiding in Mexico.

Despite the tough breaks in her personal life, Newton-John always bounced back, turning tragedy into a positive force with charities and movements ranging from cancer research to the environment.

In 1991, Newton-John turned tragedy into a cause that would help others when her daughter, Chloe, lost her best friend, Colette Chuda, to cancer.

Newton-John helped form the Colette Chuda Environmental Fund in the United States, assisted with the foundation of Australia’s Planet Ark organisation in 1993 and served as Goodwill Ambassador to the United Nations Environment Programme.

She also actively supported Melbourne’s Austin Hospital in building the Olivia Newton-John Cancer Wellness and Research Centre, and promoted the LIV-KIT device for breast cancer detection.

She received many honours including being appointed an Officer in the Order of Australia (OA) in 2006.

That followed an Order of the British Empire (OBE) honour bestowed upon her by Queen Elizabeth II in 1979.

In 2012 the National Trust of Australia named her a National Living Treasure.

One of Newton-John’s latest awards came in 2006 at the G’day LA Ball in Hollywood, where she was presented with a Lifetime Achievement Award by Travolta.

Travolta said he admired how Newton-John had survived the ups and downs in her life.

“We’ve been friends for 28 or 29 years and we have always been there for each other no matter what, thick or thin,” Travolta said.

In May 2017 the singer announced she was cancelling a tour due to the recurrence of her breast cancer, which had metastasised to her back and would be undergoing treatment at the cancer centre named after herself in Melbourne.

Newton-John married twice, first in 1984 to actor Matt Latanzi after they met on the set of Xanadu.

The couple divorced in 1995 and in 2008 Newton-John secretly wed John Easterling, the founder of natural remedy firm Amazon Herb Company.

She is survived by her daughter, singer and actress Chloe Rose Lattanzi.