Legendary Hollywood exec Ron Meyer left his job thanks to a blackmail scheme over an extramarital affair — after a downward spiral of gambling and womanizing, sources told Page Six on Tuesday.

The 75-year-old entertainment titan, who helped shape the careers of everyone from Tom Cruise to Meryl Streep, announced Tuesday that he was leaving NBCUniversal after 25 years — amid repeated attempts to extort him over his former lover.

Meyer’s ex-mistress was identified by sources as British actress Charlotte Kirk, 28 — whose later affair with Warner Bros. CEO Kevin Tsujihara, 55, brought that exec down last year.

“I recently disclosed to my family and the company that I made a settlement, under threat, with a woman outside the company who had made false accusations against me,’’ Meyer said in a statement.

“Admittedly, this is a woman I had a very brief and consensual affair with many years ago,’’ said the Tinseltown career-maker, referring to Kirk, according to sources.

“I made this disclosure because other parties learned of the settlement and have continuously attempted to extort me into paying them money or else they intended to falsely implicate NBCUniversal, which had nothing to do with this matter, and to publish false allegations about me,’’ Meyer said.

But sources told Page Six that Meyer’s statement was only the tip of the iceberg in terms of what went on behind the scenes over the extortion bid.

Meyer — a co-founder of the behemoth Creative Artists Agency before jumping to Universal to head its film division for 18 years — married first wife Ellen Meyer in 1975.

The couple had two daughters — including Jen Meyer, who was once wed to “Spider-Man’’ star Tobey Maguire — before divorcing about 12 years later.

He then married second wife Kelly Chapman in 1993, and the couple split in 2018.

Meyer didn’t say when his affair with Kirk began or ended, but sources said it started around 2012 and that the pair met a few times over the course of about a month.

Kirk — who has had bit parts in flicks such as “Ocean’s 8” and “How to Be Single’’ — then began threatening to expose the relationship, sources said. Even though it was consensual, Meyer knew that given their extreme age difference, it might not look good, sources said.

Tsujihara was forced to step down from his post last year after it surfaced he had an extramarital affair with Kirk in 2013 — and amid allegations he offered to help her career as the pair had sex.

“Ron was an idiot,’’ a source said. “Instead of telling [Kirk] he wouldn’t give in,’’ he paid her.

But then Meyer fell victim to a new shakedown attempt, the source said. It wasn’t immediately clear who was behind it.

He eventually refused to give in, and his alleged extorters ended up sending a draft lawsuit to Universal on Monday, the source said.

Meyer was out by the end of the day, the source said.

“Universal asked Ron, ‘Why didn’t you tell us you were being extorted?’ ” the source said. “He told them, ‘I thought I could handle it.’

“Universal said, ‘We can’t allow you and the company to be extorted, you should have called the FBI.’ ”

The behind-the-scenes saga came as Meyer had been dating woman after woman following his divorce — after years of allegedly grappling with hefty gambling debt, sources said.

Meyer has admitted to being a high-roller but has insisted he’s now reformed.

“The irony is that Ron is one of the most loved people in Hollywood,’’ the source noted.

“He dated a lot of women after his divorce. They may not have been the totally appropriate women for his age and status, but it was always consensual.

“He may have got into trouble with his womanizing and gambling, but it wasn’t illegal. He was just stupid. Classic gambler mentality — he got himself too deep into situations he couldn’t control.”

Reps for Kirk declined comment to The Post. Meyer’s representatives also wouldn’t comment.