Olivia Newton-John has died at the age of 73, her husband has confirmed.

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.

Writing on Instagram, Travolta said that her "impact was incredible" and signed off his tribute to the actress as "your Danny".

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

We need your consent to load this Instagram contentWe use Instagram to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences

"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.

The latter also ranks as one of the best-selling singles of all time.

Olivia Newton-John and John Travolta in Grease

The entertainer, whose career spanned more than five decades, devoted much of her time and celebrity to charities after being diagnosed with breast cancer in 1992.

In a statement posted to Instagram, her husband John Easterling wrote: "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.

Newton-John was born in Cambridge, England, to Welshman Professor Brin Newton-John and his German-born wife Irene, who was the daughter of Nobel Prize-winning physicist Max Born.

The youngest of three children, she moved with her family to Melbourne when she was five.

By her mid-teens, she was already carving out a career as a budding star, having formed a girl group with classmates called Sol Four at the age of 14 before winning a talent contest on Australian TV show Sing, Sing, Sing and a trip to the UK.

Singing duo Pat Carroll and Olivia Newton-John, aka Pat and Olivia, on the River Thames in London, UK, 1 June 1966

Although initially hesitant to travel back to the UK, she took the trip a year after winning the programme, on the advice of her mother and, once there, she recorded her first single in 1966, Till You Say You'll Be Mine.

Newton-John then formed a partnership with a friend from Melbourne, Pat Carroll, with the pair touring Army bases and clubs throughout the UK and Europe as the double act Pat and Olivia.

Her second single, a cover of Bob Dylan’s If Not For You, reached the top 10 in the UK and Australia, giving her an early taste for success before her next single, Banks Of The Ohio, topped the charts in Australia.

UK contestant Olivia Newton-John performs Long Live Love during the final dress rehearsal for the Eurovision Song Contest in Brighton, 6 April 1974

In 1974, she represented the UK at the Eurovision Song Contest with the song Long Live Love, and came in fourth place in the year Abba won with Waterloo.

She experienced further pop music success in the years following Eurovision, before the career-defining role in Grease arrived in 1978.

Initially, she was apprehensive about the role that would come to immortalise her, worrying that she was too old to play a high school student (she turned 29 while filming in 1977).

The Grease writers changed the script to allow for Olivia Newton-John's Australian accent

However, after insisting on a screen test with co-star Travolta, she took the part. To account for her Australian accent, writers changed the play’s original American Sandy Dumbrowski to Sandy Olsson, an Aussie who holidays in the US before moving there permanently.

Grease was an immediate success, becoming the biggest box-office hit of 1978.

Powered by songs such as You’re The One That I Want, Hopelessly Devoted To You and Summer Nights, the film’s soundtrack topped charts around the world and remains one of the best-selling albums ever.

Olivia Newton-John and John Travolta celebrating Grease's 40th anniversary in 2018

Arguably the most beloved musical of all, Grease’s popularity has endured and the cast reunited when the film celebrated its 40th anniversary in 2018.

Following the film, Newton-John returned to her music career, boosted by Grease. She continued performing and releasing music until her death.

Listen to Olivia Newton-John chat with Ray D'Arcy on RTÉ Radio 1 in 2019 below:

We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences

She married actor Matt Lattanzi in 1984 and the couple had a daughter, Chloe Rose, in 1986.

The couple divorced in 1995. In 2008, she wed her second husband, businessman and conservationist John Easterling, and they remained married until her death.

John Easterling and Olivia Newton-John pictured together in 2011

After being given the first of three cancer diagnoses in 1992, Newton-John became a prominent breast cancer campaigner.

Following her initial battle with the disease, she had a partial mastectomy and reconstruction.

(second from left) Chloe Lattanzi, John Easterling and Olivia Newton-John attend the Wellness Walk and Research Run in 2019

She remained cancer-free until a recurrence in 2013, then in September 2018, Newton-John revealed she had been diagnosed with cancer for the third time in three decades, telling Australian news programme Sunday Night that doctors had found a tumour in her lower back in 2017.

The singer said she was treating the illness "naturally" and was using cannabis oil made from marijuana her husband grows in California to alleviate the pain.

Olivia Newton-John performs during Fire Fight Australia at ANZ Stadium on 16 February 2020

She also underwent radiation treatment and cut sugar from her diet in a bid to overcome the cancer. She said: "I believe I will win over it."

She also said she hoped Australia would legalise medical marijuana.

In January 2019, amid reports in the US of her failing health, she shared a video message with fans revealing that "reports of my death have been greatly exaggerated".

She is survived by her husband as well as her daughter Chloe Lattanzi.

Source: Press Association