Met Gala 2018 Photos: Looks from the Red Carpet

• Rihanna, one of the evening’s co-hosts, has arrived. See the slide show above for all the famous people who ascended the steps of the Met.

• The Met Gala is not a religious affair, but tonight attendees are channeling the church for this year’s theme: “Heavenly Bodies: Fashion and the Catholic Imagination.”

True colors on the red carpet

Lena Waithe, the actress, producer and screenwriter who won a 2017 Emmy for her work the Netflix comedy “Master of None,” wore a suit designed by Wes Gordon for Carolina Herrera and draped herself in a rainbow cape. Hers was one of the more political messages of the night.

“This is like my skin, I’m proud to be in it,” said Lena Waithe, who is a lesbian. “I’ve got the community on my back to make sure they know I’ve got them all the time.”

“The theme to me is, like, ‘Be yourself,’” Ms. Waithe said. “You were made in God’s image, right?”

Rihanna takes things literally

Rihanna, one of this year’s hosts, looked like she took a spin through the pope’s closet and took the most fabulous bits. A massive headpiece, a heavily beaded mini-dress topped with a skirt and cropped jacket, and a crucifix necklace comprised the look by Maison Margiela Artisanal.

The superstar caused a tizzy on the red carpet but seemed as chill as ever while snapping a selfie with the model Ashley Graham and Eva Chen, the director of fashion partnerships at Instagram. When the singer SZA noticed Rihanna, she was visibly star-struck and zipped up the stairs toward her.

“The things we do, darling.”

Bella Hadid, wearing Chrome Hearts, said the best part of her night was seeing Anna Wintour: “I always get really, really star-struck when I see her.” Her black headpiece was attached to her floor-length veil and train. “It’s sewn into my head,” she said. “The things we do, darling.”

A warrior look for Olivia Munn, and a little bloodshed

Olivia Munn, wearing a heavy gold H&M dress and chain mail headpiece, said the look was inspired by the Crusades. “They had to sew me in on the way here,” Ms. Munn said, adding that she had been getting ready since 10:30 a.m. The ride was not without a little bloodshed. Before arriving on the red carpet, one of the links of the dress split and sliced her leg. She pulled her dress aside to reveal blood. “It’s just a little nick,” she said. “It happens.”

About the theme, Ms. Munn said: “It’s interesting because the religious theme allows more people to pull from different places,” like the Virgin Mary and Madonna, she said.

Fancy pants and a bold floral on Amal Clooney

George and Amal Clooney, a co-host of this year’s Met Gala, were this year’s A-list early birds. Ms. Clooney wore a Richard Quinn creation: a silver strapless corset-like top with dark skinny pants and a silver-and-rose-patterned train that crinkled like foil. Her hair was pulled back in a ponytail.

The couple welcomed twins Alexander and Ella in June. So where were the babies? “They’re under the dress,” joked Mr. Clooney, who turned 57 yesterday.

25 memorable looks from past Met Galas

Princess Diana in 1996. Naomi Campbell in 1995. Gisele Bundchen and Tom Brady in 2008. Take a trip back in time and check out some of the most unforgettable looks.

What is the Met Gala anyway?

Called “the party of the year,” “the Oscars of the East Coast” and “an A.T.M. for the Met,” the annual party, always held the first Monday in May, is a chance for stars to push the limits of fashion — and credit lines. Tickets cost $30,000 each. A table goes for $275,000. All proceeds go to the Metropolitan Museum of Art’s Costume Institute, the only curatorial department at the museum that funds itself.

What happens inside?

It’s a secret! For the last three years, posting on social media has been banned after the red carpet. As Vanessa Friedman, The New York Times’s chief fashion critic, writes: “There is a receiving line inside with the hosts, and guests have to file by and air kiss them. Then guests tour the exhibition (or at least, the part in the Met) on their way to the cocktail party, so they are theoretically forced to experience some culture. After cocktails, they are called in to dinner, and there is always some form of entertainment. (Last year, it was Katy Perry.)”

This year’s expected guests

Cardi B, Greta Gerwig, Tiffany Haddish, Frances McDormand, Kim Kardashian West with sisters Kendall and Kylie Jenner, Mitt and Ann Romney, Chadwick Boseman, Princess Beatrice, Zendaya and hundreds more.

Anna Wintour, the editor of American Vogue and the artistic director of Condé Nast, has been the chairwoman of the gala since 1999. This year’s co-chairs are Amal Clooney,Rihanna and Donatella Versace.

No invitation for Trump

And in case you were wondering, President Donald Trump will not be one of them. He has been a regular in the past — and proposed to Melania at the 2004 gala — but last fall, Ms. Wintour told the late-night host James Corden that President Trump was off the guest list for good.

Met Gala 2018 Photos: Looks from the Red Carpet