However, according to The Sun, Kate and Prince William did not make an appearance at Meghan's birthday party.
An insider told the publication last week: “Frogmore Cottage will host a celebration for Meghan's birthday.
“It is unlikely that the Cambridges will be invited to Meghan's 38th birthday on Sunday,” the source said.
The snub comes after months of speculation around whether this is a royal rift between Meghan and Prince Harry, and Kate and Prince William.
Prince Harry marked his wife's birthday with a touching message on their joint Sussex Royal Instagram account.
"Wishing HRH The Duchess of Sussex a very Happy Birthday 🎂" he posted, alongside a photograph of the Duchess in a stunning blue dress.
"Happy Birthday to my amazing wife. Thank you for joining me on this adventure! - Love, H"
Other members of the royal family, including Queen Elizabeth, also marked the occasion on their Instagram accounts.
Posting a photo of Meghan holding Prince Harry's hand, Her Majesty, The Queen wrote her own birthday message to her granddaughter-in-law via the @theroyalfamily account.