Many lauded the supermodel for her suave choice of attire, which featured a stylish Emporio Armani suit and chic Chanel top hat.
While Delevingne has never been one to shy away from standing out from the crowd, she has revealed in a new interview that she asked the bride's permission to wear the suit to the wedding.
Prior to the ceremony at St George’s Chapel on 12 October, the model sent Princess Eugenie a text to make sure that she approved of her sartorial choice.
“Eugenie has been a friend of mine since I was a kid and I’ve always wanted to wear tails,” she tells Grazia magazine.
“I texted her, as I wasn’t sure about it, and she was like: ‘Of course, I expected nothing else from you!’”
Their friendship goes way back, with Vanity Fair reporting that their mothers Pandora Delevingne and Sarah Ferguson attended school together in the 1980s.
The connection between Delevingne and Princess Eugenie clearly didn’t falter as they grew older, with the pair pictured linking arms at a London Fashion Week party in 2015.
The model's suit and top hat ensemble was praised on social media on the day of her close friend's wedding, with one person saying that she "won" the whole day.
"Yeah yeah Prince George and Princess Charlotte were cute blah blah but @Caradelevingne totally stole the show with this outfit," another person wrote.
Also in attendance at the wedding alongside Delevingne was her friend Derek Blasberg, sisters Chloe and Poppy Delevingne, and brothers-in-law Eddy Grant and James Cook.
Delevingne was ranked 14th place on the list, with an estimated fortune of £18m.
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