Meghan, 37, supported her friend Serena Williams as she played against Kaja Juvan in the second round match.
The new mum wore a striped L’Agence blazer with a simple black T-shirt and blue jeans, but social media users were questioning whether she is allowed to wear denim at the tennis tournament.
Firstly, Meghan wasn’t sitting in the Royal Box as Serena’s match took place on court one, not centre court where the royals usually sit.
She sat among the crowd with two of her university friends Lyndsay Roth and Genevieve Hillis.
Secondly, there is no official dress code for Wimbledon. Unlike Ascot, the rules for spectators are relaxed, unless you’re lucky enough to to be in the Royal Box.
Wimbledon’s website states that the protocol for the Royal Box is “dress is smart, suits/jacket and tie, etc. Ladies are asked not to wear hats, as they tend to obscure the vision of those seated behind them.”
That’s why when Meghan attended with her sister-in-law Kate last year, she wasn’t able to wear her hat on her head.
The Duchess of Cambridge surprised fans on Tuesday by arriving at the tennis tournament early to watch a match between British player Harriet Dart and American Christina McHale in the ‘normal seats’ on court 14.
She later made her way to centre court for Roger Federer and Lloyd Harris’ match.
The Duke and Duchess of Sussex’s son Archie Harrison Mountbatten-Windsor will be christened in a Private Chapel at Windsor Castle on Saturday 6 July.
While the couple will release official photos, the names of the baby’s godparents will not be revealed.
Serena Williams was highly tipped to be Archie’s godmother but she said she isn’t going to the christening, due to work commitments.