The look at a recent trivia night at the Colony Hotel in Palm Beach, Fla., was anything but trivial. It wasn’t modest either. Quilted bags said “money.” Feathered bags said “peacock” along with tiaras, sky blue blazers, slim white jeans and tweedy hot pants. Men wore velvet slippers. Women wore white ankle boots, espadrille wedges and Chanel spectator pumps, a perfectly named shoe for a voyeuristic poolside scene.

The crowd of 20 to 30-somethings skewed surprisingly young for a cloistered resort town that is known for its septuagenarian snowbirds, discriminatory private clubs, old-money socialites and former President Donald J. Trump’s Mar-a-Lago resort. Social observers have called it a “youthquake.”

They’re embracing venerable old places like the Colony, a midcentury jewel that was rediscovered during the pandemic, after languishing as a staid pink-and-bamboo relic. Now, it has become the kind of social media chum that tracks half its bookings to Instagram links, according to hotel management.

“Young people are discovering all the old things down here and posting about them, and the old people are amused watching them make such a fuss,” said Celerie Kemble, 48, the interior designer who, along with her mother, Mimi McMakin (both are Palm Beach natives), renovated the Colony’s lobby and 90 rooms. “It’s all kind of a hoax but it’s fun.”

The social face-lift is not limited to the Colony. The narrow island of Palm Beach — 16 miles long with many billionaires according to a 2021 Forbes ranking and a median sale price for a single-family home of about $9.9 million according to Redfin — has drawn young arrivistes from New York City and elsewhere, who fled during the pandemic. Many, at first, stayed with their parents, then bought houses and, finding life and parties better, have decided to stay.

Sofia Vergara, Kris Jenner, Kelly Klein, Daisy Soros, Tommy and Dee Hilfiger, Sylvester Stallone and his daughters, and others have been spotted in its sun-dappled courtyard this winter. Inside, dinners go until midnight in an interior that suggests a yacht off the coast of Sardinia and throbs like a nightclub, in an area where restaurants used to shut at 10 p.m.

But now the social focus is shifting to newer restaurants popular with the see-and-be-seen set.

The most difficult reservation on Worth Avenue, the town’s luxe window-shopping strip, is Le Bilboquet, an outpost of the Upper East Side French-inspired bistro, which opened in Palm Beach in 2021. Lola 41, a seafood restaurant from Nantucket, opened at the White Elephant hotel in 2020 with a buzzy courtyard that is great for multigenerational people-watching. Nearby is Cucina Palm Beach, a small Italian restaurant that becomes a late-night hot spot with a disco ball and bottle service.

A new English-style social club, Carriage House, designed to appeal to a younger demographic, is expected to open later this year. It is modeled afterAnnabel’s in London, with bars, dining and game rooms — but no dance floor to bother the neighbors.

“Palm Beach can be an intimidating place if you don’t have a connection,” said Sarah Wetenhall, 45, who with her husband, Andrew, bought the Colony Hotel in 2016 from her father-in-law and gave it a refresh, removing the jacket and tie dress code for dinner, booking celebrity trainers like Isaac Boots, and replacing the old-world cabaret space with pop-up shops.

“We set out to lower the wall and the privet hedges,” Ms. Wetenhall added, “and now people say we’re like a club without dues.”

Places like the Colony Hotel, which has become an influencer-friendly destination for the younger set, offer something different from the local clubs, which have traditionally revolved around golf, tennis, bridge and cocktails. Recent events included a dinner for Vogue, a party for Martha Stewart’s CBD gummies, a Veronica Beard runway show and art lectures by Christie’s.

Bettina Anderson, 35, a third-generation Palm Beach resident who models for magazines and works for the Paradise Fund, a charitable organization she founded with other young philanthropists to protect the environment and at-risk citizens, said she has seen the hotel come alive. “It’s still what it was when my parents came, but it’s much younger.”

Nick Hissom, 29, runs Wynn Fine Art gallery on Worth Avenue, selling the blue-chip contemporary collection of his stepfather, Steve Wynn, the casino mogul, as well as emerging artists through Aktion Art at the same location. He moved from New York City in 2020 and joined a wave of other gallery owners who set up during the pandemic, including Pace and Lehmann Maupin.

“I used to come visit on the family boat, and now we’ve moved down here and have immersed ourselves,” Mr. Hissom said of himself and his boyfriend, Kameron Ramirez, a 23-year-old film producer.

Michael Gregson Reinert, 30, moved to Palm Beach from Charleston, S.C., a few years ago, and positioned himself as a social media expert and fashion brand connector.

“I just kind of integrated myself here without pretensions,” said Mr. Reinert, who was recently featured in a Palm Beach Illustrated magazine spread, posing by the sea with his jawline against the horizon. “I can fill a room with the right people, so that if a brand wants a shoot or a dinner, everyone is beautiful.”

Some longtime locals are rankled by the younger social set who are demanding instant entry into clubs or suddenly packed private schools, or pressuring the architectural review board to allow bigger homes that raze gardens.

“They’re not so much rich people’s problems as challenges,” said Liza Pulitzer, a real estate broker whose mother was Lilly, the local fashion icon. “But it’s part of buying into a life here.”

On a recent Thursday night, Cavalier Galleries held an opening for the photographer Christophe von Hohenberg, drawing the well-heeled bons vivants. Nick Mele, 39, who is known around town as a Slim Aarons type, was photographing the scene.

“In the eight years since I got here, it’s become a different place and it’s booming,” Mr. Mele said, lamenting the lack of parking spots on Worth Avenue. “I just hope we don’t lose all our old Palm Beach characters.”

One of those characters walked in moments later: Jane Holzer, the Warhol “It girl” and subject of Tom Wolfe’s 1964 essay “The Girl of the Year.” She has deep Palm Beach roots and rents Le Bilboquet its space. A show of her Warhol portraits, including one of herself, was up at the nearby Ben Brown Fine Arts. Ms. Holzer, 81, does not resent the influx of young people.

“They’re all my friends and I think it’s the best thing that has happened to this town,” she said as a stream of well-wishers, including Mr. Hissom and Ms. Anderson, greeted her with reverence. “Andy used to love watching the kids in New York, and now I get to do the same thing down here.”