CANNES, France — “This might look like a ton of fun, but don’t forget this is also work,” said the movie producer Harvey Weinstein, long after midnight on the steps of the Hôtel du Cap-Eden-Roc in Antibes, France, against a backdrop of flowing Champagne, crashing waves and a strolling band playing tracks by the Beatles. The setting was the 69th annual Cannes Film Festival, and Mr. Weinstein, on the French Riviera for two weeks to make film deals, would later host a party onboard the Odessa II yacht with the billionaire businessman Len Blavatnik.

“You are constantly at work in Cannes, morning, noon and night,” Mr. Weinstein said, cellphone in hand. “It doesn’t stop.”

Indeed, although Cannes has long been the film festival with the most star power and glimmering parties, this year more than any other the power of the red-carpet economy has been on show for all to see in an ever-spinning carousel of premieres, news media junkets and high-wattage events. Charles Finch of Finch & Partners, a consultancy that advises brands on Hollywood partnerships, said that as the movie industry has shrunk, the big sponsorships that were once the province of major studios have been co-opted by major luxury houses instead, with the related transformation of the Croisette into a catwalk.

Megabrands such as Dior and Chopard spend millions of dollars on five-star hotel suites on this busy stretch of Mediterranean seafront, grooming, dressing and bejeweling starlets for a moment in the spotlight a stone’s throw away at the Palais.

“The studios came to Cannes for cultural gravitas and indie credentials that would give their movies added weight, spending a great deal of money doing so,” Mr. Finch said. The festival’s focus on international cinema meant a more global spotlight than American-centric award ceremonies, he said. “Now, it’s the turn of big brands to step up and do the same thing.”

Mr. Finch would know. He hosted his annual star-studded dinner Friday night, alongside the watch brand Jaeger-LeCoultre, on the palatial terraces of the hotel.

Clive Owen rubbed shoulders with George Miller, the director of “Mad Max” and this year’s main competition jury president, while his fellow juror Mads Mikkelsen mingled with the likes of Heidi Klum, Charlotte Tilbury, Gael García Bernal, Jack O’Connell and Johnny Coca, the perennially kilted Mulberry creative director. Dominic West held court at the center of the room, and at dinner the actress Rebecca Hall giggled with Mick Jagger, who was resplendent in a crushed plum-hued jacket, and later shamelessly cut the line at the buffet.

Just 24 hours later, a lucky few hundred guests traveled once again along the winding coastal roads back to the Hôtel du Cap-Eden-Roc for the Vanity Fair party, hosted by the magazine’s editor, Graydon Carter.

After a lavish dinner upstairs, co-hosted by Richard Plepler, the chairman of HBO, the scene headed downstairs and onto the decks for an after-party that resembled a 1950s movie set: The hotel’s lush gardens had been uplit in misty pinks and yellows, elegant sandy-hued umbrellas positioned amid the rocks, and the Vanity Fair logo gleamed like sunken treasure from the bottom of the pool. Dozens of security heavies with earpieces lurked discreetly in the bushes, ready to boot any foolhardy crashers willing to try their luck. (There were plenty.)

“It’s so much fun tonight,” said the model-of-the-moment Kendall Jenner in a midnight blue satin wrap gown with sparkling black tassels by Mathieu Mirano. “I feel like all my friends are here.”

Nearby, Kate Hudson chatted with Peter Dundas, the creative director for Roberto Cavalli, and Kirsten Dunst, who was full of praise for the designer of her gown, the London-based Michael van der Ham.

“He is one of the most talented guys in the business, and I want him in the spotlight,” she said, while leaning by the bar. “Tell everyone about this amazing outfit.”

Jodie Foster continued to accept well wishes for her film “Money Monster,” which debuted two days earlier, and Chloë Sevigny, bedecked in tweed and lace by Alessandra Rich, did an enthusiastic rendition of the cancan. Russell Crowe was also in high spirits, telling fellow revelers that if they went to see his new movie, “The Nice Guys,” also starring Ryan Gosling, “please wear underwear, because you’ll laugh your pants off.”

This was not a problem for a flat-capped Leonardo DiCaprio, who charged scowling through the crowd at lightning speed before setting up a base in the shadows.

The party was co-hosted by the jewelry brand Chopard, also an official partner of the film festival, as well as the co-host of its own yacht party earlier. Along with Colin Firth and his wife, Livia, Chopard celebrated the latest Green Carpet collection as part of a collaboration with Gemfields, the precious stones supplier, to produce ethically sourced emeralds. Julianne Moore wore several pieces to the opening ceremony, which glimmered among the gold sequins on her Alexander McQueen gown.

“The great thing about Cannes is that beyond the glitz and glamour, the red carpet can be used to promote important causes in a public arena that has unparalleled reach,” said Mrs. Firth, the founder and creative director of Eco Age, a brand consultancy that helps companies become more sustainable.

Kering, the French luxury conglomerate that owns such names as Gucci, Stella McCartney and Alexander McQueen, had the same idea. In addition to creating the “Women in Motion” series of talks that explore the position of women in the film industry, the group hosted the Cannes presidential dinner Sunday night honoring the work of Susan Sarandon and Geena Davis, 25 years after the release of “Thelma & Louise.”

As the actresses took selfies, Ms. Sarandon said that the female-centric road-trip classic would most likely never have been made today given what she called “a lack of imagination” by male film executives.

“It would probably end up as an animation,” she said, after having whipped off her heels to collect her award, her comment cheered by Juliette Binoche, Vanessa Paradis and Jean Paul Gaultier. “Whereas women can see a woman or a man in a leading role,” she added, “I don’t think it’s as easy for a guy to see a woman in a leading role and say, ‘I’ll get behind that.’ It is still a cultural thing.”

Her seatmate at dinner, Salma Hayek, gave the subject a more positive spin.

“There’s a lot of work to be done still, I know,” Ms. Hayek said, before sitting back in her rose pink ruffled Gucci gown. “But I truly believe that this is an issue that is part of more conversations that ever before. It’s amazing to see and hear.”