OLIVIA NEWTON-JOHN’s daughter Chloe was so upset about her mom’s obsession with plastic surgery that she staged an intervention – led by none other than Olivia’s “Grease” co-star John Travolta!

Chloe, 27, asked John to help after watching her mother’s beautiful face get distorted from too much Botox and other fillers, says a source. “John’s the ONLY person in the world Olivia would have listened to about her plastic surgery,” the source explained.

“Even her husband (John Easterling) didn’t want to go there because she’s so sensitive about it. “Of course, John brought up his concerns in his usual loving and sensitive way, so Olivia was open to hearing him out. She didn’t promise John she’d stop everything, but she did politely tell him that she appreciated his concern and would think about it.”

Olivia has previously denied having plastic surgery.

Celebrity plastic surgeon and author Dr. Anthony Youn, who has not treated Olivia, told The ENQUIRER it appears the 65-year-old singer-actress had injec¬tions of fillers in her cheeks. “I also suspect that she may have had Botox injections into her forehead,” he continued. “Olivia is such a natural beauty that plastic surgery is definitely something she doesn’t need.”

The “Let’s Get Physical” singer, who’s been married to natural health businessman Easterling since 2008, has remained close friends with John, 59, since the two starred together in the 1978 musical “Grease.” They even reunited last year for a charity Christmas album.

MEANWHILE, Chloe, whose father is actor Matt Lattanzi, has her own problems. She’s admitted to battling anorexia as well as a drug and alcohol addiction. According to the source, Chloe, an aspiring singer who reportedly is no stranger to altering her own face with cosmetic procedures, contacted John because she knows how much her mother respects him.

“Now that Chloe is clean and sober, she realized that inner beauty is more important than what’s on the outside – and that’s why she reached out for help,” said the source. “Olivia appreciated her daughter’s concern and was genuinely moved by John’s interest. Now it’s just a matter of time to see if she takes his advice.”