The Duchess of Cambridge is famously sports mad and serves as patron for some massive sporting organisations, including the Rugby Football Union and the All England Lawn Tennis and Croquet Club.
And, when it comes to Wimbledon, the royal mum-of-three is a regular sight at the tennis championships, rooting for the players and energetically joining in with the applause. In fact, famed tennis ace Roger Federer even counts her as a friend.
It appears they've got quite the friendly relationship, with the Swiss player even attending Kate Middleton's sister Pippa's wedding to James Matthews in 2017. The same year saw Kate personally congratulating Federer on his win at Wimbledon as Prince William stood by.
Following Roger's Wimbledon victory, and the stylish duchess surprised fans by giving him not one, not two, but three kisses to congratulate him on his historic win. Meanwhile, the happy tennis player shared a friendly handshake with Prince William afterwards.
Roger, it appears, goes beyond a mere acquaintance in William and Kate's elite circle of celebrity friends as rumours even bubbled up that he gave Prince George a private tennis lesson at the Middleton residence in Bucklebury.
He later described the young royal as a "sweet boy", boasting budding tennis skills, reports MyLondon.
And the tennis champ isn't the only celeb to be part of the Cambridges' close-knit group of friends as they're rumoured to be tight with David and Victoria Beckham too, as the power duo were on the guest list for the 2011 royal nuptials.
Prince William, meanwhile, has his own celeb connections. Elton John was chummy with Princess Diana, so that's a given.
Then there's Eddie Redmayne, who reminisced about their rugby days at Eton, saying: "I did play rugby with Prince William. I always felt a bit sorry for him because basically any school you played, all they wanted to do was tackle Prince William and they could say, 'I tackled Prince William'."
And let's not forget Kate's bond with culinary queen and former Bake Off judge Dame Mary Berry – they've been seen baking up a storm together, with Mary even coaxing out some of Kate's secrets from her early days dating William at St Andrew's University in Scotland.
