Kate, Duchess of Cambridge and Meghan, Duchess of Sussex, right, sit in the Royal Box on Centre Court ahead of the women's singles final match between Serena Williams of the U.S. and Angelique Kerber of Germany at the Wimbledon Tennis Championships, in London, Saturday July 14, 2018.
On Sunday, Kate and husband Prince William will watch the men's singles final on Centre Court.
Serena Williams lost her match at Wimbledon this year, but luckily, she had her friends there to support her.
But before they could take their seats, the pair met with ball boys and girls, wheelchair competitors and junior players ahead of the day's play.
Williams said: "We've always had a wonderful friendship".
While Williams - who gave birth to her first child, daughter Alexis Olympia, 10 months ago - may not have won, she still praised Kerber for her hard work.
Shortly after her engagement, the Duchess of Sussex joined the Duke and Duchess of Cambridge and Duke of Sussex at the first annual Royal Foundation forum in February. The Duchess of Sussex displaying effortless Hollywood chic in her eye-catching flares.
The Duchess of Cambridge and the Duchess of Sussex have attended their first Wimbledon together.
USA Serena Williams will take on Germany's Angelique Kerber in the ladies finals today.
Photographed entering the stadium, the two ladies appeared to be chatting away happily and giggling with one another.
After the match she praised Williams, saying: "Serena you are a great person and a champion, you are coming back and you are such an inspiration for everybody, for all of us and every person watching".
Princess Kate was dressed in go-to favorite, Jenny Packham, Saturday while Meghan made a nod to her American roots, dressing in Ralph Lauren. "You know, I've known Meghan [Markle] for years, so it was good to see my friend happy".