Beneath the placid sea of air kisses, Carolina Herrera gowns and artful floral arrangements at recent society galas both here and in Palm Beach roils a tidal wave of buzz about a gentleman of a certain age who just came on the market.

Leonard Lauder, the 80-year-old son of cosmetics giant Estée Lauder, recently broke off his engagement to Linda E. Johnson — and the news has every social X-ray east of Bergdorf Goodman discreetly elbowing herself forward.

Since breaking off his engagement to Linda E. Johnson in December, eligible billionaire Leonard Lauder is one hot commodity.Getty Images

“My darling, they are all lined up. And why wouldn’t they be?” purrs socialite Muffie Potter Aston of the women angling to become the next Mrs. Leonard Lauder.

“He’s handsome, he’s charming, he’s well-dressed. If there is an It girl, he’s the It guy. [Lauder’s availability] is certainly something that has been discussed in a variety of different social circles and it is quite apparent.”

While not a downtown playboy with chiseled cheekbones and an appetite for clubbing, Lauder comes with all the trappings of immense wealth: several billion dollars; a master-of-the-universe title; homes in Manhattan, Palm Beach and Aspen; and an extensive art collection that would make the Louvre envious. He has devoted his life to philanthropy, cutting a dapper figure in his tailored suits and pink ties.

“Everybody wants to marry Leonard — your friends, your dog, even your father,” quips an uptown doyenne who has had the “privilege” of sitting across the dinner table from Lauder on many occasions. “He appreciates women. And he’s got a wicked sense of humor. He can be self-deprecating,” she adds.

Though Lauder is worth a whopping $7.6 billion, many ladies insist his allure goes beyond his position on the Forbes list of wealthiest Americans (he’s No. 56).

“There are a lot of women who don’t mind his bank account. For me, it’s not about that,” says Aston, who, for the record, is happily married with two children. “There are a lot of frogs with bank accounts — he’s actually the prince.”

The tycoon’s green light flicked on in December, when he broke up with Johnson, the 55-year-old head of the Brooklyn Public Library and a reed-thin marathoner originally from Philadelphia.

Page Six exclusively reported that the chairman emeritus of Estée Lauder and the chic brunette canceled their holiday party, announcing in an e-mail to friends that they were also separating.

“We are afraid that we must cancel Sunday’s holiday party,” the e-mail read. “Sadly, we have made the difficult but mutual decision to go our separate ways.”

The news came just months after the couple postponed their Philadelphia wedding, which was to be held in August, because he reportedly thought it was too soon after the death of his wife, Evelyn, who died from ovarian cancer in November 2011. Johnson and Lauder still vacationed in Sardinia, which would have been their honeymoon.

After splitting with his statuesque gal pal, Lauder didn’t seem to be crying into his fancy pocket square. Days later, he was hitting the party circuit, attending a soiree thrown by Tommy and Dee Hilfiger, where sources told Page Six that “ladies on the guest list were in a tizzy to get close” to the scion. And, along with co-hosts David Koch and Wilbur Ross, he donned his signature red carnation at the annual New Year’s Eve Coconuts bash at the Flagler Museum in Palm Beach.

“I know a lot of people are enthusiastic that he is single,” says unattached socialite Kelly Bensimon, who compares Lauder to Aristotle Onassis. “He’s well-bred, well-fed and well-read. He’s iconic. It’s rare when a Mr. Lauder is single.”

Although he moves in a rarefied stratosphere where other fabulously wealthy men hunt skinny blondes with their checkbooks, Lauder doesn’t leave behind a messy trail of ex-wives, relationship casualties or a reputation of collecting arm candy.

“He’s not a player. That’s why women are lined up for him. A catch like him comes around maybe once a decade,” says elite matchmaker Janis Spindel, who would “love” to help him find a mate.

The heir was married to Evelyn Lauder for 52 years. The couple have two sons, William and Gary. His elegant wife, who was a senior executive at Estée Lauder and oversaw fragrance for the company, became a powerhouse in the fight against breast cancer, helping to create the iconic pink ribbon for awareness and establish the Breast Cancer Research Foundation. Though petite with inviting brown eyes, she was a titan in the world of New York philanthropy. After her death, Lauder continues to devote himself to Evelyn’s causes, including throwing their annual Hot Pink Party.

“Leonard and Evelyn were a great love story. They were very much devoted to each other personally and professionally. They were the ultimate power couple of New York,” says Aston.

Last year, the widower told Vegas Magazine that he was not bored, but he was “lonesome,” adding, “I’m in the midst of reshaping my own life. It’s not easy after 52 years. When we were married, I was 26. We formed our own life. Now I have to form a new life.”

He seemed to have written that new chapter with Johnson, but our society snitch says trouble arose when it came time to live together. Johnson balked at moving into Lauder’s E. 67th Street penthouse, which still has his late wife’s imprint.

“If she was going to live in [Lauder’s] apartment, she didn’t want signs of Evelyn around. She didn’t want to be competing with Evelyn’s memory.”

Through his spokesman, Lauder declined to comment for this article.

Observers of the uptown set are quick to note that it will take more than just a wardrobe full of Oscar de la Renta gowns to catch his eye. Prospective mates need to fill the shoes of his powerful mother, who built the cosmetics powerhouse from scratch, as well as his wife.

“I know he loves pretty and charming women,” says David Patrick Columbia, founder of the New York Social Diary, which chronicles the cocktail parties and galas above (and sometimes below) 59th Street. “He spent his life living with two women who were more than just pretty and charming. They were dynamic and remarkable. [Evelyn] had her own life and professional career. And that appealed to him. He’s a special man because he lived his life with a lot of powerful women.”

Aston agrees: “[Evelyn’s] are very big shoes to fill. Leonard is such a brilliant man, he will eventually find the right woman.”

A love of travel is also a must, as Lauder splits his time among Palm Beach (in the mansion he inherited from his mother), Aspen, Manhattan and Vienna, where Evelyn was born.

And then there’s his appreciation of art.

Lauder, who began collecting postcards when he was a young boy, is the world’s largest collector of Cubist paintings. Last April, he gifted the Metropolitan Museum of Art with 78 works by artists such as Picasso, Braque and Gris. The collection is valued at more than $1 billion.

For his next mate, Spindel suggests a woman in the 55-to-60 age range.

“Someone very attractive, sophisticated but understated, very philanthropic, who is going to enhance the life that he already has. He needs a woman who — believe it or not, as old and bright as he is — he will be able to learn from, because that’s a big turn-on for men,” says the matchmaker.

And while he’s not exactly a spring chicken, Upper East Side publicist R. Couri Hay says Lauder has the energy of a man in his 50s. “He’s got a twinkle in his eye. He’s probably the most coveted dinner companion anyone could get,” says Hay. “He’s well-aware of his eligibility, and I wouldn’t say he’s hiding.”