There was no shortage of celebrities onstage last weekend at the first installment of this year’s Coachella Valley Music and Arts Festival in Southern California, where Doja Cat, Billie Eilish and even Will Smith performed.

Ms. Eilish surprised spectators by joining Lana del Rey for the folk-rock singer’s first Coachella set since 2014. Mr. Smith, who started his career as a rapper, also shocked many in the audience by performing a rendition of his song “Men in Black” with dancers dressed as aliens during the reggaeton singer J Balvin’s set.

But some of the highest-profile performers at the festival weren’t there to work: Rihanna and ASAP Rocky, along with Taylor Swift and Travis Kelce, came as spectators, even if neither couple could exactly blend in with the crowd.

At Coachella — an orgy of brand activations, parties and musical performances — celebrities are but one reliable component. Another is fashion, which typically tends toward the ostentatious. That was mostly the case last weekend, during which these 15 looks stood out — some for being opulent, others for being over-the-top and a couple for being surprisingly simple.

Of the many outfits worn by the singer and rapper during her set, this get-up involving few clothes and strategically arranged extensions might have stolen the show — if only by a hair.

Gwen Stefani: Most Hollaback Girl!

The singer, who reunited with No Doubt at Coachella, harked back to her punk style as the band’s lead singer in an ensemble that mixed plaids with mesh.

A jeweled choker and a silver bracelet added sparkle to the musician and band leader’s iridescent pink suit.

Ice Spice: Most Tied Up!

Instead of copper curls, the rapper had flowing orange-red locks, which she wore with a skintight, lacy I.AM.GIA bodysuit with ties at the legs, arms and chest.

Shakira: Most Unraveled!

The singer, who at Coachella announced a world tour promoting her new album, took the stage in a fiery shredded minidress that exposed plenty of skin and resembled a knitting project.

Lil Uzi Vert: Most ‘Seinfeld’!

A difference between this voluminous white top and “the puffy shirt” that inspired punchlines on “Seinfeld”? The rapper wore this version with bravado.

Paris Hilton: Most ‘Cowboy Carter’!

While Beyoncé was not present at Coachella, her presence was felt in Western-inspired outfits, like this pairing of flirty dress with cowboy hat and boots by the heiress who has moonlighted as a singer and D.J.

Simu Liu: Most Unassuming!

Yes, the sleeveless top flaunted the actor’s toned arms, but his festival attire was still relatively simple compared with what many others wore.

Lauryn Hill: Most Electric!

Among the visually stimulating elements of the rapper’s look were silver hair beads, heavy blue eye makeup and a vibrant yellow Balmain suit.

Barry Keoghan: Most Logos!

Somehow, the actor’s gratuitous combination of Burberry check scarf, Versace top, Burberry check shorts and Nike sneakers … worked.

Xin Liu: Most Tin Woman!

The Chinese singer’s metallic top and pants evoked space-age garments by Thierry Mugler and Paco Rabanne. They were made by Syban Velardi-laufer, a costume designer in London.

Brittany Howard: Most Stained Glass!

Glowing would correctly describe the way the singer looked onstage in this colorful patchwork-style sequined caftan.

Campbell Puckett: Most Pookie!

In a TikTok video, the influencer known as Pookie described her outfit of flouncy top, leather microshorts and knee-high boots as “girlie rocker.”

Taylor Swift and Travis Kelce: Most Coachella!

Mood boards for “festival style” the world over will likely now be populated with references to the singer’s and the professional football player’s outfits, which seemed effortlessly thrown together but were almost certainly constructed with care.