PARIS — Sixty years to the day after showing his first collection under his own name, Yves Saint Laurent, the designer who is synonymous with French fashion and who died in 2008, is once again taking Paris by storm. Or rather, his creations are.

From Saturday through May 15, 50 pieces from the couturier’s vast body of work will be shown among the permanent collections at five of France’s most prestigious museums: the Louvre, the Musée d’Orsay, the Centre Pompidou, the Musée d’Art Moderne de Paris and the Musée Picasso Paris. And the Musée Yves Saint Laurent, in the designer’s former headquarters on Avenue Marceau, is to display sketches, Polaroid photographs and rare toiles that illustrate the processes and craftsmanship that go into creating couture.

Organizers say the contemporaneous displays of “Yves Saint Laurent aux Musées,” 18 pandemic months in the making, will be the first time a couturier has been honored in so many classic institutions at once. But it will be yet another of Mr. Saint Laurent’s firsts, including being the first couturier to embrace ready-to-wear, the first to take fashion inspiration from street style and one of the first designers to put models of color on the runway. And it may put to rest the perennial debate about whether high fashion belongs amid high art.

Mouna Mekouar, the co-curator of the show and a contemporary art specialist (this will be her first fashion exhibition), said that while fashion and art traditionally have existed in parallel worlds, that separation no longer applies.

“I think that, in 2022, we live in a time when we no longer need to ask the question about whether fashion is art, or whether art is art,” she said during an interview at the Café Beaubourg, in the shadow of the Centre Pompidou.

“Today, we’re living in a multi- and trans-disciplinary universe made up of connecting links, so the old labels don’t really make sense anymore,” she added. “I don’t think one can understand any fashion designer, whomever they may be, without considering the contemporary creation around them. By the same token, I don’t think we can understand a contemporary artist without also looking at what’s happening in fashion.”

None of the institutions, she said, hesitated for an instant when she proposed the joint show.

The genius of Saint Laurent, Ms. Mekouar said, was that he blurred the lines between fashion and art from the beginning.

“He was looking at various civilizations and forms of art and responding to the art of his time,” she said. “He was announcing the arrival of the 21st century. His gaze was pluralistic: there’s no hierarchy, just multiple centers of interest.

“He completely assimilated an artist’s work to reinvent it,” she continued. “Even when the reference is direct, there’s always a twist that’s his own. And his work still has meaning all over the world today because he did it before anyone else.”

So multifarious were Saint Laurent’s references that the exhibition could have gone “in a thousand different directions,” she said. To keep it focused, Ms. Mekouar; Stephan Janson, her co-curator; and Madison Cox, president of the Fondation Pierre Bergé-Yves Saint Laurent, worked closely with museum directors and curators to blend selections with the holdings at each institution.

At the Centre Pompidou, for example, 500 Polaroids of YSL friends, muses and models including Kate Moss, Carla Bruni, Stella Tennant and Naomi Campbell give a table display a Warholian air. A dress from the Picasso collection of fall-winter 1979, with undercurrents that reflect the work of the French artist Sonia Delaunay, is displayed in the Delaunay room. A green coat from the Scandale collection of 1971 stands next to “Made in Japan,” the Pop work by Martial Raysse, a contemporary of the couturier.

Then there are the celebrated Mondrian dresses of fall-winter 1965, which highlighted the work of the Dutch painter Piet Mondrian to a French audience — a decade before the Pompidou acquired “Composition in Red, Blue and White II.” In the display, a YSL Mondrian dress and the painting stand side by side for the first time.

“This project was particularly resonant for the Pompidou,” said Xavier Rey, the museum’s director, “because not only was Yves Saint Laurent the first to connect couture to the art he loved and collected, but also because the museum was where he chose to bid fashion farewell, in 2002” — a reference to the couturier’s last fashion show, a 45-minute retrospective. The film of that event is to be screened at the museum.

At the Musée d’Art Moderne, installations have been rearranged and the lighting dimmed to accommodate clothes that highlight a different facet of 20th-century art, with a denim coatdress from the designer’s spring-summer 1970 Rive Gauche ready-to-wear line paired with striped painted panels by Daniel Buren, a onetime street artist. And at the Musée d’Orsay, which specializes in 19th century works, the touchpoint is not art, but literature. Marcel Proust, whose works were a lifelong inspiration for Saint Laurent, is referenced indirectly through one of the designer’s trademarks — Le Smoking, or tuxedo dressing for women — a nod to the once-radical concept of masculin-féminin (currently known as gender fluidity).

Placed before the d’Orsay’s great clock at the entrance to the Impressionist collections are five tuxedos, including Saint Laurent’s very first, from 1966, as well as two belle époque-inspired gowns. Both were designed for the Proust Ball of 1971 — one, worn by Jane Birkin, was crafted of ivory crêpe with leg-of-mutton sleeves and guipure lace while the other, modeled by the ball’s hostess Marie-Hélène de Rothschild, was made of ivory satin with black trim.

They all are displayed within view of Édouard Manet’s 1863 painting “Le Déjeuner sur l’Herbe,” or “The Luncheon on the Grass,” another of Mr. Saint Laurent’s recurring obsessions. Further along in the Impressionist collections, an alcove dedicated to graphic arts shows Saint Laurent’s sketches of clothing designs and pictures of YSL’s loyal clients, such as Hélène Rochas, wife of the designer Marcel Rochas, in a black velvet gown with a décolleté of cattleya orchids in white satin.

In the Louvre’s gilded Galerie d’Apollon, home to the French crown jewels, four ornately embroidered jackets celebrate the glories of France and its savoir-faire.

One jacket called Homage à Ma Maison, the designer’s tribute to his petites mains and made of organza heavily encrusted with rock crystal and embroidered with gold thread, was displayed near King Louis XIV’s collection of objects in carved rock crystal. A heart pendant made of rhinestones and poured glass, part of the semiology Saint Laurent used to designate a favorite model in a runway show, joined a display of replica jewels.

Mr. Cox, the foundation president and Mr. Bergé’s widower, noted that he believed Saint Laurent would be thrilled with the company his work is keeping. “While Mr. Saint Laurent perhaps wasn’t the most modest person in the world,” he said, “I think he desperately wanted to be considered an artist. He was an artiste manqué.”

Geographically and figuratively, the event covers a lot of ground. Even so, Ms. Mekouar and Mr. Cox said it represents just a sliver of the themes yet to be mined from the 7,000 or so YSL garments, 50,000 accessories and thousands of sketches for collections, décors and costumes preserved in archives all over France. And that does not include troves like the 250-plus pieces and prototypes donated to the foundation in 2019 by the YSL muse Betty Catroux.

“I’m hoping that this type of exhibition can be applied to other locations,” Mr. Cox said, “so we can get out of the idea of the fashion exhibition as we’ve known it.”

Said Mr. Rey of the Centre Pompidou: “It’s our duty to present art in all its forms. Through today’s designers we see that, more than ever, fashion has a legitimate place.”