Oscars 2018: Why is everyone talking about this outfit?

Olympic figure skater Adam Rippon's outfit caused a stir at the Oscars

As always fashion and the Oscars go hand in hand... Here are the outfits trending on social media.

Olympic medallist and figure skater Adam Rippon was one of the first people to arrive on the red carpet in an unconventional outfit.

Along with a suit, he was wearing a leather harness designed by the creative director of Moschino, Jeremy Scott.

Rippon posted a selfie on Instagram to show off his look - which also included a leather bow tie - prior to arriving on the red carpet.

"Just something casual," he wrote as a caption to the picture.

It got the thumbs-up from supermodel and fashion icon Tyra Banks, who called the Olympic skater "fierce".

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Rippon, who is the first openly gay US winter Olympian, lit up Twitter with comments about his red carpet look:

Screenwriter and director James Ivory wore a shirt with Timothee Chalamet's face on it.

The bromance between James Ivory, director and screenwriter of Call Me by Your Name and star of the film, Timothee Chalamet continued at tonight's Oscars.

Ivory, 89, who is nominated for best adapted screenplay, wore a shirt with lead actor nominee Chalamet's face on it.

Rita Moreno at the 1962 and 2018 Oscars

One of the biggest red carpet moments was 86-year-old Rita Moreno arriving in the same dress she wore when she won her Oscar in 1962 for West Side Story.

The 56-year-old dress was made in Manila in the Philippines and included a new neckline but the same black opera gloves.

Tiffany Haddish wore a traditional Eritrean dress

Tiffany Haddish wore an embroidered cape, headdress and dress called a "zuria".

The comedian and actress, who is presenting an award tonight, explained what was behind her traditional outfit.

"My father is from Eritrea, and he passed away last year, and he said that if ever I make it here I have to honour my people. So here I am!"

Tiffany Haddish on stage with Maya Rudolph at the Oscars.

Haddish caused a stir again as a presenter on stage with Maya Rudolph.

She changed outfits, wearing an Alexander McQueen dress she wore at the Girls Trip premiere in July and when she hosted Saturday Night Live in November.

She joked on the show that she was an "outfit repeater" and said the dress would be making another appearance and the comedian kept her word.

Timothee Chalamet and Armie Hammer star in Call Me by Your Name

Call Me by Your Name stars Timothee Chalamet and Armie Hammer caused a storm when they appeared on the red carpet together.

Hammer was too ill to attend Saturday's Independent Spirit Awards and appeared on Chalamet's phone on FaceTime at the ceremony.

Fans were extremely pleased to see the pair reunited on the Oscars red carpet.

Elisabeth Moss, Gina Rodriguez, Salma Hayek, Sally Hawkins and Mira Sorvino appeared in pastel embellishment.

Unlike the Golden Globes and Baftas, the Oscars were awash with bright colours, with stars making a nod towards the Time's Up movement with pin badges.

Tonight's fashion showcased glamorous designs, with pastels and embellishment on the top of the hot list.

Elisabeth Moss, Gina Rodriguez, Salma Hayek, Sally Hawkins and Mira Sorvino all reflected this trend, which got the seal of approval on social media.

The Washington Post's Robin Givhan wrote of the colourful fashion choices, "the solidarity seemed to be more in actions and attitude, with moments such as actress Nicole Kidman dipping into an interview with Sandra Bullock on ABC for a hug and a declaration of affection".

Leading actress nominee Saoirse Ronan in Calvin Klein.

Lady Bird star and leading actress nominee Saoirse Ronan and her sugary-pink Calvin Klein gown was a big hit with fashion writers.

Vogue's style editor Edward Barsamian praised the dress for its "cheerful, optimistic tone".

"The bow-trimmed gown is poised to sit alongside other memorable Oscar red carpet moments, including Nicole Kidman's mandarin-inspired Galliano for Dior Couture dress in 1997 and Julia Roberts' black and white Valentino stunner from 2001," he wrote.

Chadwick Boseman in custom Givenchy at the Oscars

Black Panther's Chadwick Boseman gave a nod to Wakandan fashion in his custom-made Givenchy suit.

Despite the film being released too late to receive any nominations at this year's Oscars, it was still the talk of the ceremony.

Fellow cast members Lupita Nyong'o and Danai Gurira also created a fashion moment on the red carpet.

Lupita Nyong'o and Danai Gurira on the red carpet.

Marvel's Black Panther also got an honourable mention during the ceremony, with Jimmy Kimmel praising it for its commercial success and ground-breaking content.