The AIDS charity group amfAR usually holds a gala during New York Fashion Week in February, but that was shelved because of the Omicron variant. So when art collectors John and Amy Phelan offered to host a fund-raiser at their modern, 17,000-square-foot estate in Palm Beach, Fla., last Saturday, the money followed.

And so did their neighbors on South Ocean Boulevard. With several guests living on what’s known as Billionaires Row, the fund-raiser almost felt like a block party.

“You’ve got Stephen Schwarzman, John Paulson and Willis Dupont,” Steve Wynn, the casino mogul, who arrived for cocktails around 7 p.m., wearing a blue velvet tuxedo jacket without a tie. “We’re all here and it’s a chance to get dressed up.”

Another neighbor, Tommy Hilfiger, happened to be the night’s honoree. “I know who you are,” Mr. Hilfiger said to Victoria Hagan, the interior designer, as if from across a picket fence. “I tried to get you to do one of my houses.” In his slim houndstooth suit, he gave neighborly hugs all around, including with Dennis Basso, the old-school furrier, and Douglas Friedman, the tattooed photographer.

About 375 guests each paid $5,000 to attend, raising about $5.3 million that night — not bad for amfAR’s first foray into Palm Beach.

Ms. Phelan, a former Dallas Cowboys cheerleader who presides on various art boards and whose husband is an investment fund manager, held court in her living room with windows that soared nearly 30 feet high. A work by Willem de Kooning graced the gas fireplace mantle. Other blue-chip artists grabbed the eye and Ms. Phelan, in a gold gown that made her look like an Oscar statue, was on a first-name basis with some of them.

“I love Andy and I love Dolly,” she said of a candy-colored portrait of Dolly Parton by Andy Warhol, which hung near a monumental sized painting by Jean-Michel Basquiat.

Some guests — who preened in eye-popping colors, aggressive patterns, velvet slippers and stiletto heels — were art-struck. “I hope this is a sleepover party,” said Emily Hampshire, the “Schitt’s Creek” actress and the event’s master of ceremonies, as she lounged precariously in a green vintage Dior pantsuit on top of a Jeff Koons bust. “I’m ready to move in.”

Outside by the pool, canapés of lobster, steak and tuna tartare flew by like petals in a subtropical wind. Around 8 p.m., dinner was announced and the crowd pushed through multicolored strips of fabric, as if inside a carwash, entering a giant tent framed in Lilly Pulitzer-pink neon lights that flashed “Art” and “Party.”

Guests dined on chopped Mediterranean salad and chicken with heirloom roasted vegetables. They listened attentively to speeches about how Covid treatments benefited from H.I.V. research. They listened less attentively to Simon de Pury, who auctioned off works by Gilbert & George, Tom Sachs and others (crypto accepted).

Around 10 p.m., Sylvester Stallone, another neighbor, took the stage in all black to introduce Mr. Hilfiger, who said, “Thanks, Sly,” before thanking friends and neighbors. “This is unreal to me,” he concluded.

Then Christina Aguilera came onstage in a flurry of glittering purple confetti, with earrings the size of chandeliers, and ended the night with three songs.