Meghan has been living in California with husband Harry and their two children for more than three years, since the couple stepped down as working royals for a life a personal and financial freedom in March 2020.
The royal family’s official account on X, formerly known as Twitter, did not post a birthday message for the duchess for the second year running.
Usually just working members of the monarchy are recognised on royal social media channels.
The official X account of the Prince and Princess of Wales marked Meghan’s 41st birthday last year, but there were no posts on Friday celebrating her August 4 anniversary.
Meghan was photographed a few days ahead of her birthday leaving a restaurant with Harry in the celebrity enclave of Montecito in California where they have established a new life for themselves and their children Archie and Lilibet.
The duke and duchess made headlines earlier this week when they called young innovators and campaigners to congratulate them on being awarded a share of a multimillion-dollar prize to boost their efforts.
Harry and Meghan rang some of the 26 recipients who will receive the financial award from the Responsible Technology Youth Power Fund – and joked their kids were “incredibly grateful”.