The death was announced by her husband, John Easterling. She had been living with a breast cancer diagnosis since 1992 and announced in 2017 that the cancer had returned and spread. For years she was a prominent supporter of cancer research, starting a foundation in her name to support it and opening a research and wellness center in metropolitan Melbourne, Australia. Of English descent, grew up in Australia. Ms Newton-John has amassed No.1 hits, chart-topping albums and four records that have sold more than two million copies each. More than anything, she was likable, even loved. In the early phase of her career, Ms. Newton-John seduced listeners with a high, supple, warm voice that blended amicably with the kind of pop pop that, in the mid-1970s, often passed for country music. Her chart performance made that blur clear. He scored seven Top 10 hits on Billboard’s Country chart, two of which were back-to-back No. 1 hits in 1974 and ’75. First came ‘I Honestly Love You’, a serious statement co-written by Peter Allen and Jeff Barry, followed by ‘Have You Never Been Mellow’, a wing of a song written by the producer of many of her biggest albums, John Farrar. . “I Honestly Love You” also won two of the singer’s four Grammys, for record of the year and best female pop vocal performance. The combination of Ms. Newton-John’s consistently good-natured music – never a critical favorite – and elegant but stark image led many writers to compare her to earlier blonde creations such as Doris Day and Sandra Dee. “Innocent, I’m not,” Ms. Newton-John told Rolling Stone in 1978. “People still see me as the girl next door. Doris Day had four husbands,” he said, yet she was still considered a “virgin.” A foray into cinema in 1978 aimed to leave the singer’s pristine image behind, starting with ‘Grease’. Her character, Sandy, went from a pigtailed square hit by John Travolta’s bad boy Danny to a gum-smacking mean girl. “Grease” became one of the most successful movie musicals of all time, surpassing even “The Sound of Music.” Its soundtrack was the second best-selling album of the year, beaten only by the soundtrack for “Saturday Night Fever,” which also starred Mr. Travolta. The “Grease” soundtrack spawned two No. 1 hits, sung by both co-stars, including the manically sultry “You’re the One That I Want” and the doo-wop romp “Summer Nights.” A ballad Ms. Newton-John sang alone, “Hopelessly Devoted to You,” earned the film its only Oscar nomination, for best song. Applying the evolution of her ‘Grease’ character to her singing career, Ms Newton-John named her next album ‘Totally Hot’ and featured on the cover in shoulder-to-toe leather. The album, released in late 1978, went platinum, yielding the rock-oriented “A Little More Love” with the line “Whereed my innocence?” The album featured Ms. Newton-John singing in a somewhat stronger voice. Although her sales declined as the 1970s turned into the 1980s, the beginning of the decade saw her embark on the strongest commercial period of her career, culminating in the single “Physical,” which spent 10 weeks at the top of the Billboard chart. The magazine later named it the greatest song of the 1980s. Olivia Newton-John was born on September 26, 1948, in Cambridge, England, the youngest of three children born to Brinley and Irene (Born) Newton-John. Her mother was the daughter of Nobel laureate physicist Max Born. Her Welsh-born father was an MI5 intelligence officer during World War II and then served as headmaster at Cambridgeshire Boys’ High School. When Ms. Newton-John was 6, her family immigrated to Melbourne, Australia, where her father worked as a college professor and administrator. At 14, she formed her first group, Sol Four, with three girls from school. Her beauty and confidence soon earned her solo appearances on local radio and television shows under the name “Lovely Livvy.” On the go!! Show” she met the singer Pat Carroll, with whom she would duet, as well as her eventual producer, Mr. Farrar, who later married Ms. Carroll. Ms Newton-John won a local TV talent competition whose prize was a trip to Britain. While there, she recorded her first single, “Til You Say You’ll Be Mine”, which was released by Decca Records in 1966. After Ms Carroll moved to London, she and Ms Newton-John formed the duo Pat and Olivia, which toured Europe. When Ms Carroll’s visa expired, forcing her to return to Australia, Ms Newton-John stayed in London to work on her own. In 1970, she was asked to join a crudely constructed band called Toomorrow, formed by American producer Don Kirshner in an attempt to repeat his earlier success with the Monkees. Following his grand plan, the group starred in a science fiction film written for them and recorded its soundtrack. Both projects sold out. “It was terrible, and I was terrible at it,” he later told The New York Times. Her debut solo album, ‘If Not for You’, was released in 1971, the title track being a cover of a Bob Dylan song. After a few stints in the United States, Ms. Newton-John released the album “Let Me Be There” (1973), which led to a Grammy for Best Female Country Vocal Performance. Two key changes in pop music boosted her career in that decade: the rise of “soft rock” as a reaction to the harder genres of the late 1960s, and the incorporation – some would say the sterilization – of country music, which also marked by stars like John Denver and Anne Murray. The latter trend became a topic in 1974, after Ms. Newton-John was named the Country Music Association’s female vocalist of the year over more traditional stars such as Loretta Lynn and Dolly Parton. The protests led to the formation of the short-lived Union of Country Entertainers. However, after Ms. Newton-John recorded her album, “Don’t Stop Believin’,” in Nashville in 1976, the friction subsided. The second phase of her career, which began with “Grease”, found further success through a duet with Andy Gibb, “I Can’t Help It”, followed by an attempt to expand her acting career with the musical film 1980’s “Xanadu,” with Gene Kelly. While the film flopped, its soundtrack went double platinum, with hits like “Magic” (which was No. 1 on Billboard for four weeks) and the title track, which was recorded with the Electric Light Orchestra. In 2007, a Broadway camp based on the film opened. Ms. Newton-John’s thrilling “Physical” also yielded the first album video to be released, with music videos for all of the album’s tracks. “Olivia Physical” won the 1982 Grammy for Video of the Year. He was reunited with Mr. Travolta in the 1983 film “Two of a Kind,” an attempt to repeat the success of “Grease.” But the film disappointed even as its soundtrack proved popular, especially the song “Twist of Fate”. Ms Newton-John was made an Officer of the Order of the British Empire in 1979. By the mid-80s, her career had cooled. For several years she quit her job to care for her daughter, Chloe Rose, who she had with her then-husband, actor Matt Lattanzi. They had met on the set of “Xanadu” and married in 1984. They divorced in 1995. That same year, she met Patrick McDermott, a cameraman whom she dated for the next nine years. In 2005, Mr McDermott disappeared while fishing off the coast of California. Ms Newton-John was never a suspect in his disappearance. Three years later, a US Coast Guard investigation said evidence suggested Mr McDermott had been lost at sea. In addition to her husband, she is survived by her daughter, Chloe Rose Lattanzi; her sister, Sarah Newton-John; and her brother, Toby. After learning she had breast cancer in 1992, Ms Newton-John became a staunch supporter of research into the disease. Her Olivia Newton-John Foundation Fund is dedicated to researching herbal treatments for cancer, and she opened a cancer research and wellness unit named after her at Austin Hospital, outside Melbourne. Despite her own treatments, she continued to release albums and tour, but failed to make any headway on the charts. And he continued to act in films and on television. In May 2017, she revealed that her cancer had returned and had metastasized to her lower back. He published his memoir Don’t Stop Believin’ in 2018. To the end, Ms. Newton-John firmly believed in her audience-friendly approach to music. “It bothers me when people think because it’s commercial, it’s bad,” he told Rolling Stone. “It’s completely the opposite. If people like it, so be it.”