The post also contains an image of Kate with her father, Michael Middleton, from when she was a young girl.
For the special day in the United Kingdom, other members of the royal family also posted their own snaps to celebrate.
The Duke and Duchess of Cambridge have released an unseen photo of Prince William and Prince Charles hugging to celebrate Father's Day in the UK. Over the past few years, the Duchess of Cambridge has given us numerous heartwarming photos of Prince William and their children, Prince George, Princess Charlotte and Prince Louis, to bring a smile on our faces.
The Prince's birthday also coincides with Father's Day in the United Kingdom, which is celebrated on June 21, months earlier than in Australia (September 6).
William turns 38 on Sunday, and was photographed by Kate in the grounds of his Anmer Hall mansion on the Sandringham estate in Norfolk, romping with Prince George, Princess Charlotte and Prince Louis. Charlotte stole the show at the event as she waved to the crowd, and William and Kate couldn't stop smiling as they stood by all three of their adorable kids.
Kensington Palace uploads pictures of Prince Williams kids ahead of his birthday
On Sunday, Kate and William shared two more photos, in which all three mini Cambridges pile on top of their dad.
The British royals have come out of isolation to attend select public engagements but are yet to meet up in person. "Charlotte is the image of her Granny".
The Clarence House Instagram account also released pictures of Prince Charles with Harry and William at the Cirencester Park Polo Cup in 2004.
"And there's no one there to, kind of, help you, and I definitely found it very, at times, overwhelming". And on Friday, Kate spoke with employees at the Fakenham Garden Centre in Norfolk about how the family-run business has been impacted in the lockdown.
Prince William visited Smiths The Bakers in King's Lynn, which is close to Anmer Hall, and he shared with the owners how his kids have discovered their love of cooking during quarantine.
Waste water study finds coronavirus was already in Italy in December
She is the spokeswoman for the institute and said that the results of the study would be published in a journal next week. Researchers in Barcelona found coronavirus in wastewater dating back to 41 days prior to their first reported case.