About two months ago, Eli Russell Linnetz moved into a house built in the mid-1980s by the actor Dennis Hopper. Mr. Linnetz had spent the last few years as a kind of Venice Beach Goldilocks, moving until he found a studio that felt just right.

For the 32-year-old multi-hyphenate — we’ll start with fashion designer, for simplicity’s sake — this was what finally felt right: a metal fortress with a roof curved to resemble the crest of a wave. Hard and looming on the outside, airy and exposed on the inside.

On a video call, Mr. Linnetz climbed a floating staircase beneath an impossibly high wood-beamed ceiling, pointing out original features like an angular glass bathtub and “the room where Dennis Hopper died.” The scope was too much for our screens. Walking across the property, toward a small white house where he now lives, Mr. Linnetz discovered gardenias blooming in the yard.

One of his earliest renovation decisions was to tear up the studio’s floors and install plywood from the time it was built. This choice was characteristically meticulous and nostalgic. Mr. Linnetz tends to fixate on small details in the service of telling a good story.

Before his first-ever runway show in May of last year, in which he introduced a collection made in collaboration with Dior, he explained: “I want the zipper, the buttons, the beads, the color to be in perfect harmony. You can have really expensive beautiful glass beads, but if they’re not sewn on properly, they don’t tell the story you want to tell.”

If Mr. Linnetz sounds like one of those filmmakers bent on making sure every prop on their set is authentic and era-accurate, it’s because he’s also that. A director. And a screenwriter, a photographer, a stage designer and a music producer, who first began dabbling in the fashion industry in 2018. That dabble spiraled into a full-fledged brand, ERL, part of a family of brands supported by Comme des Garçons and its retail arm, Dover Street Market. Last year, ERL was named a winner of the prestigious Karl Lagerfeld Prize for young designers. The line is now carried in more than 220 stores.

For his next act, Mr. Linnetz will take one of fashion’s most exclusive stages as guest designer of the Pitti Uomo men’s wear fair. The title has been held by many of fashion’s greats: Jean Paul Gaultier, Vivienne Westwood and Dries Van Noten in the 1990s; Virgil Abloh, Telfar Clemens and Grace Wales Bonner in more recent years. His runway show is scheduled for June 15 in Florence, Italy.

Yet Mr. Linnetz, to put it bluntly, would almost rather be working on his screenplay at home in Venice, Calif. “The show is interrupting my filmmaking,” he said.

Once, on a visit to New York in 2021, I asked Mr. Linnetz what about fashion was exciting to him, considering his other occupations.

“It’s literally not,” he said that November. “I don’t know how I ended up here.”

As a child, he often sketched dresses, he conceded, and later made a prom dress for a friend, then helped pay for his tuition at the University of Southern California by sewing costumes for the opera program. But otherwise, Mr. Linnetz said, “I have almost no connection to fashion, other than it is the medium that’s directly in front of me as a way to express the world around me.”

That world is surfer chic with Americana influences: vintage-inspired graphic tees, swollen skate shoes, patchwork flared jeans, bright gradated knits, several variations on a hoodie.

“I almost feel like the Manchurian Candidate,” he said. “Like someone calls me every morning to say, ‘You will design today,’ and my brain turns off, and I’m almost hypnotized.”

A year and a half later, he still describes fashion the same way, as if it’s a compulsion or illness beyond his control: “It’s always with you. Can it just go away?”

But he says it with a grin.

Behind the Music

At first, Ronnie Cooke Newhouse, the influential creative director, didn’t know what to make of Mr. Linnetz, when he asked for a meeting in Paris in 2016.

“You meet people from L.A. who are kind of out of the fashion system” — and here she acknowledged a slight personal bias — “and they all seem to do many, many, many different things. And, most of the time, many, many, many different things very badly. They’re designers who don’t design, they’re actors who don’t act, they’re editors who don’t edit.”

So when she met the 20-something Mr. Linnetz, who said he had already directed a Kanye West video, produced music and worked for the playwright David Mamet, “I was just like, ‘OK, here we go,’” Ms. Newhouse said.

Except, she learned, Mr. Linnetz had done those things, and a bit more, and not badly at all.

He was a child actor in Los Angeles — with Disney credits including the 2000 animated film “The Emperor’s New Groove” — until his bar mitzvah, when he decided to quit acting to “focus on being Jewish,” he said. At his temple, he met Mr. Mamet, who invited him to the set of his TV show “The Unit.”

On the day of that visit, there happened to be a costume contest, Mr. Linnetz, then 15, recalled. He made Mr. Mamet a judge’s robe from light-blocking fabric and a wig from cotton balls. “He was like, ‘That’s so odd, but come back tomorrow,’” Mr. Linnetz said.

When he wasn’t in school, he was assisting Mr. Mamet, including on Broadway. One of his tasks was printing out emails sent to Mr. Mamet, who would write his replies on a typewriter.

At U.S.C., he majored in screenwriting, minored in opera and joined a fraternity. (He had always been interested in hypermasculine rituals; in high school, he wrestled.) He made a short film during his senior year starring Sawyer Spielberg, set in 1960s El Paso. But after graduation, the filmmaking didn’t take off. He turned instead to 3-D animation. A friend who worked with Kanye West (now known as Ye) showed him Mr. Linnetz’s art; Mr. Linnetz, who had met Ye a few years earlier, was brought in to work on cover-art concepts for “The Life of Pablo.”

The relationship escalated. Among several other things, Mr. Linnetz can claim responsibility as “creative director of fabrication” for the 12 nude celebrity sculptures in Ye’s “Famous” video — the one with Taylor Swift, Anna Wintour, Bill Cosby and at least two U.S. presidents sleeping together in a colossal bed.

In 2017, when Kim Kardashian returned to Instagram after she was robbed in Paris, her first posts were Polaroids shot by Mr. Linnetz, who encouraged her not to look at the camera: “So much before the robbery was her looking to the camera — the selfies. I was like, ‘Let’s do something where people are observing you so you’re not asking anything from them, and they can make their own decisions about you.’”

Working with the couple made him realize how art and photography could influence culture. But Mr. Linnetz also wanted to break out on his own. Opportunities arose to work with other performers, like Lady Gaga for the visual direction and stage design of her alien-robot-rock opera residency in Las Vegas.

By the time he asked Ms. Newhouse to meet, Mr. Linnetz wasn’t pitching a specific project — he simply wanted to work with her. She took a liking to him.

“He was adorable,” Ms. Newhouse said of Mr. Linnetz, who can seem both impish and like an old soul in the span of one conversation. “I just felt he had something.”

She asked him to direct an advertisement in 2017 for Comme des Garçons’s Andy Warhol fragrance. The next year, he met the brand’s president, Adrian Joffe. Just as his creative relationship with Ye grew quickly, so did this one. Mr. Linnetz was “kind of brilliant,” with “a rare confidence,” Mr. Joffe said in an email.

Almost as a dare — “baiting him,” Mr. Joffe said — he asked Mr. Linnetz to make something for the opening of Dover Street Market Los Angeles. “He’d never made clothing before,” Mr. Joffe said. The resulting pastel corduroy shirts ended up selling out in a week, he said. “He’s just good.”

Mr. Joffe offered Mr. Linnetz his own label under Dover Street Market Paris’s brand development program.

At the time, Mr. Linnetz saw the opportunity as a way to escape the last few harried years of living adjacent to mega fame. (In the much-memed words of Lady Gaga: “no sleep, bus, club, another club, another club.”)

“I created ERL to get away from all this music industry celebrity stuff,” said Mr. Linnetz, who was looking for “something more meditative.”

For ERL, which released its first full collection in 2020, he would shoot all the campaigns himself. He would work almost entirely by himself. He would live quietly; he doesn’t drink or do drugs, he said, or enjoy going to parties or even leaving Venice, where he is happily isolated from the fashion world at large, with a newly adopted dog named Einstein.

He sees the irony in this thinking now: “It’s weird to go and create something super-personal and then have everyone want to be a part of it.”

California Couture

“Have you seen the movie ‘Escape From L.A.’?” Mr. Linnetz asked in May of last year. He described a scene from the campy 1996 disaster film in which Kurt Russell and Peter Fonda surf on a tsunami wave while trying to chase down Steve Buscemi in a Cadillac.

The scene was his inspiration for the Dior ERL show set in Venice. The runway emerged from the beach with two large waves on either side, half-enclosing the audience, threatening to wash away all the fashion people.

“It’s this moody, blue, grungy menace,” Mr. Linnetz said, meant to spiritually complement the clothes, which were alternately electric and metallic in color, with loose silhouettes and shiny, swaggering accents. “It’s a weird, twisted, colorful Californication of Dior. A lot of the logos say ‘California Couture.’”

Kim Jones, the artistic director of Dior Men, invited Mr. Linnetz to co-design the line out of a desire to support young talent. “We have a lot of collections a year,” he said — at least four — and working with another designer can help “take you out of the bubble that you sometimes get stuck in.”

He found Mr. Linnetz’s initial approach to Dior’s archives novel: The young designer decided to focus on the year 1990, when Gianfranco Ferré, then the artistic director, was leaning into opulence. Mr. Linnetz chose 1990 only because it was the year he was born.

“He reminded me of when I had my label when I was younger,” Mr. Jones said. “I saw a lot of how I work in him — very fast, decisive, clear.”

His first solo runway show, for Pitti Uomo, will be more extravagant, Mr. Linnetz said. He will be introducing Eli Russell, a new line of tailoring and evening wear — sweeping suits in rich textures, baggy and baroque, with even more shiny metallics, to be worn by surfer-models flown in to Florence from Southern California.

“The final result is somewhere between impractical and practical, comfortable and intolerable,” Mr. Linnetz said. “This first iteration really feels like dress up. But some of the suits are, like, $15,000 to $20,000, so it’s expensive dress up.”

“I put a lot of importance on this one show because I don’t know how many I’ll ever do,” he continued. He had no intention to do another after the Dior collaboration. And he feels torn, now, between thinking “this is kind of silly” — just wanting to work on the third draft of that screenplay, an “exploration of American male friendship” about two friends starting college in the 1970s — and perhaps going too big in Italy.

“If you do something bigger, you’re suddenly confronted with the ridiculousness of everyone’s desperate desire to go viral or have a crazy moment,” said the man who once put Kid Cudi in a wedding dress and veil.

At the same time, while modeling a sequined top hat he made for the show, he expressed an intention to create a “barrage that leaves people utterly speechless.” Mr. Linnetz can’t help but contradict himself — or maybe it’s just that he contains multitudes. Is he the next “big star in the fashion world,” as Mr. Jones predicted, or someone who only came to fashion accidentally, whose imagination and ambition to tell stories stretches far beyond the medium of clothing?

“Every 10 minutes, I’m like, ‘Why did I do this?’” Mr. Linnetz said of his upcoming show. “Oh well, I guess someone has to do it.”