The appearance comes one year after the royal duo made their first joint solo outing at the prestigious sporting tournament.
All eyes on the Duchess of Cambridge, the Duchess of Sussex and Pippa Middleton as they hit the Royal box.
Mother-of-three Kate stunned in a green crepe Dolce and Gabanna dress with gold buttons that she previously wore in 2016 during a visit to Vancouver.
Former actress and new mum Meghan wore a Hugo Boss skirt with a brush stroke print and pleats, and Givenchy shirt. She completed her look with a cream Stella McCartney Grace clutch.
Meanwhile, Kate’s sister Pippa Pippa stepped out wearing a stunning white dress, covered in a blue floral-print. According to @KateMCambridge, Pippa's frock is by Anna Mason.
Meghan and Williams are close friends, with Williams attending her wedding to Harry last summer.
When asked about the negative press, Williams said she never reads anything about Meghan in the news.
“She couldn’t be a better friend to me. Low moments, high moments, she’s always there,” Williams said.
“That’s all I want to be to her.”
The duo's day out comes just days after Meghan was slammed by royal fans after she instructed her royal security personnel to inform spectators at Wimbledon not to take photos of her.
Despite being a public figure, Meghan insisted that she was at the Grand Slam in a 'personal capacity' so to watch her friend Serena William play, and therefore off duty.
Having been previously dubbed 'Duchess Difficult' after rumours of her diva demands made their way from the palace and into the public, the new mum is now being mocked for her 'no photos' request, earning the nickname 'Princess Privacy'.
Earlier this week, Kate and Meghan were also seen spending time together at the Polo where they watched their husbands Prince William and Prince Harry take part in a charity match.
The pair were all smiles as they cheered and chatted from the sidelines with their adorable children, Master Archie Harrison, Prince George, Princess Charlotte and Prince Louis.
WATCH MEGHAN'S SECURITY STOP FANS FROM TAKING PHOTOS