The fashion industry's top-billed event, the annual Met Gala, is an invitation-only fundraiser held for New York's Metropolitan Museum of Art's Costume Institute.
The Gala is held on the first Monday of May every year.
It is known for its outrageously innovative themes and, this year, the theme was 'Camp: Notes on Fashion' and was based on Notes on Camp, an essay written in 1964 by American author Susan Sontag.
This led to interesting, innovative fashion on the pink carpet. Take a look:
Salma Hayek wore a black, gold and cream Gucci dress, and a gold-leafed crown and poufy black tulle sleeves.
Penelope Cruz looked chic in a black and white ensemble.
She was wearing a Chanel dress, along with a bag by the same maker, in Christian Louboutin shoes and sported Atelier Swarovski by Penelope Cruz earrings.
Gal Gadot wore an optical white cape dress, black bodysuit in silk knit, black high-boots, headband in silver-finished metal with crystals and pearls.
She also wore jewelry by Tiffany & Co.
Zoe Saldana, who hasn’t been to the Met Gala since 2016, wore a Michael Kors gown with a big slit up the leg, with a matching necktie tied in a bow around her neck.
She also wore some large purple flowers in her hair to complete her look, along with some shimmering eyeliner.
Lupita Nyong'o walked the pink carpet in a Versace gown with slivers of neon green, sky blue and hot pink hues that created a rainbow aesthetic, along with butterfly wings and tulle. She finished her look with candy-coloured jewels.
Lady Gaga stripped into as many as four looks.
She arrived in a voluminous fuschia pink dress that had giant bows and a never-ending train and then removed it, only to reveal her '80s-inspired, all-black strapless gown.
She removed that dress as well to be in a figure-hugging shiny solid pink dress, only to undress again and finally appear in a black sparkling set of undergarments, above.
Katie Holmes wore a purple tulle dress by designer Zac Posen.
Emily Blunt wore a gold Michael Kors Collection gown with a gold floral hat by Stephen Jones.
Kristen Stewart wore sequin black crop top and white pants by Chanel. She completed the look with bleached eyebrows and vibrant orange hair.
Emma Stone wore a shimmery Louis Vuitton jumpsuit.
Dakota Johnson wore a berry dress with a bleeding gem heart at the center.
She finished off her look with a silver headpiece.
Katy Perry walked the pink carpet dressed as a chandelier.
The creation was designed by Moschino.
Celine Dion wore an Oscar de la Renta metallic bodysuit with fringe-detailing and a plunging neckline.
Jared Leto wore a long-sleeved red silk gown encrusted with jewels from Gucci. But the real showstopper was the decapitated wax-like replica of Leto's own head, which he carried around like a purse.
Janelle Monae in her Picasso and Dali-inspired look created by Christian Siriano.
Mindy Kaling's look was inspired by what she wore onscreen in Ocean's 8.
She wore a gold sequined gown from Moschino featuring a bow shoulder. The bulky look was complete with chandelier earrings and a blonde hairdo
Emma Roberts wore a Giambattista Valli Couture dress, Jimmy Choo shoes, and Irene Neuwirth jewels.
Elle Fanning wore a bright colored Miu Miu crop top and pants.
She completed the look with nail art.
Idris Elba and Sabrina Dhowre debuted as a married couple. The two tied the knot on April 26 this year.
Benedict Cumberbatch arrived with wife Sophie Hunter.
Benedict wore a Labassa Woolfe suit, and rocked the white three piece suit with a white fedora and accessorised with a emerald green brooch and walking stick.
Sophie opted for a flowy lilac gown.
Sophie Turner and Joe Jonas got married just five days ago at a surprise wedding in Las Vegas.
Sophie wore a custom-made pantsuit from Louis Vuitton, whereas Joe wore a turtleneck and black pants.
Harry Styles walked the carpet with Gucci creative director Alessandro Michele.
Styles chose to wear a black lace top with sheer sleeves and high heels.
Hailee Steinfeld wore a green and purple ruffled dress with a huge black bow in her curly hair.
But what was most notable was the message on the dress: "No photos please".
Ezra Miller carried a face mask on a stick, hiding his own face painted with five optical-illusion eyeballs next to his real eyes, equalling seven eyes in total.
Michael Urie stepped out in a pinstripe suit made by Christian Siriano.
Zoe Kravitz, the Big Little Lies actress, wore a Saint Laurent cutout black sequin gown with shoes to match.
She also wore Anabela Chan earrings with diamond stud and a big pearl stud by Harry Kotlar.
Her bracelets were by Yvan Tufenkjian and AMWAJ Jewelry and ring by Le Vian Jewelry.