Billionaire John Paulson is engaged to his much-younger girlfriend, sources tell Page Six, while he’s still embroiled in a bitter divorce battle with his ex.

The Wall Street giant ditched Jenny Paulson in 2021 after 21 years of marriage for dietician Alina de Almeida, and the former couple has been locked in an uproariously acrimonious split ever since.

Now Page Six hears that John, 68, is engaged to his girlfriend — even while the bitter divorce from Jenny continues to play out.

A source close to the couple confirms, “John and Alina have been together for two and a half years. They are very happy together and have gotten engaged.”

Bloomberg News seemed to have let the cat out of the bag first: The outlet’s Amanda L. Gordon referred to De Almeida, 35, as Paulson’s “fiancée” in an article interviewing the financier about his support for Donald Trump’s re-election campaign.

De Almeida was also listed along with Paulson as a host of a big fundraiser in Palm Beach, Fla., that reportedly raked in more than $50 million for the GOP candidate.

A source tells us that beyond the Bloomberg mention, “The word ‘fiancée’ has been said,” among Paulson and pals relating to De Almeida, “but I don’t think anyone has seen a ring.”

The source added of the alleged engagement, “He’s trying to be discreet so as not to get Jenny all riled up.”

Paulson, who’s worth at least $4.7 billion, is still in the midst of divorce — even though he left Jenny for De Almeida three years ago.

A source told Page Six at the time that Jenny was devastated, and that she only learned he filed by reading about it in Page Six.

“He has made it so humiliating because of his unseemly speed of taking a girlfriend and filing for a divorce so quickly after a good summer, with no advance notice or even courtesy. It’s unseemly and disrespectful that he couldn’t wait.” said a source at the time.

We already heard rumblings back in October 2022 that Paulson was eyeing marriage to De Almeida.

Paulson told us at the time: “Unfortunately our marriage didn’t work out. Divorces are common, but difficult. Alina and I are very happy together. I wish Jenny can find happiness, too.”

Paulson — who famously made $20 billion betting against the housing market before the 2008 crash — did not have a pre-nup.

The former spouses have been fighting over estates in the Hamptons and Aspen, Colo.

In July 2022, Jenny accused the billionaire of setting up a “secretive web of trusts” to hide money from her, according to court documents. In December, he tried to get the case dismissed.

As part of their ongoing legal war, Jenny has also accused him of using a “sham” real estate deal to take $10 million out of a family trust, while his lawyers blasted her suit as a “selfish money grab.”

We even got dragged into it in March — when John accused Jenny of hiring a private investigator to look into De Almeida, and leaking deets to Page Six.

(We’d previously reported that De Almeida got a DUI in 2018).

But documents obtained by Page Six claim that Jenny did not retain the gumshoe named in John’s briefs. A PI also confirmed in a letter submitted to the court that Jenny did not retain his services, and that he’s had neither “direct or indirect communications” with Jenny.

Robert Cohen, an attorney for Jenny, told Page Six when reached for to comment on this story, “all Jenny is asking in the litigation is her right to an equitable division of marital assets under [New York] law, including her share of any assets allegedly secretly and fraudulently transferred by Mr. Paulson to trusts he set up over many years behind her back.”

“Mrs. Paulson has no interest in commenting on or embarrassing any companion of Mr. Paulson,” Cohen added in a statement. “Her first priority remains the children, for whom she has primary responsibility, and their happiness.”

But James T. Smith, counsel for Paulson, responded in a statement: “There were no assets fraudulently or secretly transferred to trusts. Mrs. Paulson was aware of the trusts since at least 2006. She is trying to take money from her children. It’s unconscionable.”

Paulson’s attorney, Smith, also stated that, “Mrs. Paulson was well aware of the divorce prior to the first Page Six article. They had discussed separating for a couple of years, attended marriage counseling, and Mrs. Paulson had already retained divorce counsel well before the actual filing.”

De Almeida’s company is called Effective Lifestyle, and she used to post pics of herself in workout gear as well as diet tips before making her profile private after news of her relationship with Paulson made headlines.

She was recently profiled in the Palm Beach publication Palmer, giving advice such as: “Chew your food slowly and take small bites,” and, “By hydrating before meals, you’ll also curb your hunger and wind up eating less.”