The Love Actually star, 73, and the British fashion journalist, also, 73, had been rumoured to be dating after they were spotted dining out together in Rome in August 2021, but this was their first official public appearance as a couple.
Social media may have exploded with surprise that the rakish actor and the frosty fashionista are an item, but ultra stylish Nighy is a natural fit for a front row coupling.
Read more here: Anna Wintour's love life to date as she arrives at Met Gala with rumoured partner Bill Nighy (Yahoo Style, 3 min read)
The Pirates of The Caribbean star has a deep appreciation of clothes, style and fashion and frequently appears on Best Dressed lists.
We take a look at how Nighy dressed himself for success.
As a 16-year-old Nighy described himself as "an average mess... disabled by Romanticism" with his hair grown long. Then he hitchhiked to Paris and was struck by the sight of a stylish Frenchman in a suit and shades, riding on a motorbike with a woman wearing a Chanel suit and bare feet, and that was when he began to "take clothes seriously."
Watch: Bill Nighy walks the red carpet with Anna Wintour
Nighy trained as an actor and began his career on the London stage, hanging out in the Bohemian bars of Soho. While he may be famous for playing a rock star in Love Actually, it was not the style of a rocker that he embraced but that of the Mods, and he began a life-long enduring love of suits.
He has said: "I was originally a Mod, but have transcended beyond over time. I’m a modernist and I’m against all those b*****ks like dandy and dapper et cetera.
"I’m now at a sweet spot where I’m in between Mod and fine modern classic."
Suits you sir
He is now famous for his collection of blue tailored suits from London's Savile Row and is even rumoured to have turned down film roles because he did approve of the outfits they required.
But while Nighy appears to cut a fine figure on the red carpet in his illustrious wardrobe - he has revealed it is actually an insecurity in his own appearance that leads him to always dress so smartly.
He once confessed: "I know it’s all nonsense and I know there is nothing wrong with the way I look but I have never been particularly confident in that area and a suit helps me out.”
Read more here: 'I hate my body': Bill Nighy explains why he always wears suits (Independent, 2 min read)
Dedicate follower of fashion
Nighy was in a relationship with Brideshead Revisited star Diana Quick from 1982 to 2008 and the pair made a very stylish couple. They are parents to 38-year-old actor and filmmaker Mary Nighy.
It's not only fine clothes for himself that he appreciates - he also admires a chic suit on women too.
He has said: "If I ruled the world, every woman would have a Chanel suit in her wardrobe. The Parisian ideal: little or no make-up, great hair, no stockings with heels, and a Chanel suit with no handbag. The recklessness of the look appeals to me."
Wintour's signature style is a tailored suit, often Chanel, and huge sunglasses.
More recently The Hitchhiker's Guide To The Galaxy star went viral when he took a Sylvanian Families toy rabbit as his date to the 2023 Oscars.
Read more here: Bill Nighy reveals why he took a tiny ketchup-stained rabbit to the Oscars (Evening Standard, 2 min read)
Over the years Nighy has been named on the Best Dressed lists of GQ, Esquire, Mr Porter and Vanity Fair.
But the modest man has confessed he struggles to even watch himself on screen, "because all my fears about my inadequacies are confirmed."
While he may have battled demons in the past, Nighy has been a "sober alcoholic" since 1992 and is often to be spotted around London enjoying fine dining and of course rerail therapy, and is by all accounts a humble and gracious selfie-giver.
He said: "I never expected anyone to want to come up to me in the street, to want my photograph or autograph."
Classic, understated and a true British gentleman - Nighy appears to be the perfect red carpet accessory. And Wintour is known to always demand the best.