The royal couple met volunteers and operational staff at Windsor Guildhall to thank them for their involvement in the late monarch's committal service, held on the grounds of Windsor Castle.
WATCH: Prince George and Princess Charlotte walk between their parents at Queen's funeral
Taking to their official Instagram page, William and Kate shared a sweet video of their visit. Captioning the post were the words: "Thank you to all those who have worked so tirelessly to ensure that everyone visiting Windsor over the past two weeks has had a safe and positive experience.
"It was a pleasure to meet just a small number of staff and volunteers today - we are hugely grateful for all of your efforts."
William and Kate took to Instagram
Fans flocked to leave their messages for the Prince and Princess and they were so delighted to see the pair. One wrote: "The Royal Family is lucky to have you both. You both carry yourselves so well."
A second added: "Dear both of you, how beautiful you are, such a lovely kindness of heart." A third replied: "What a lovely thing to do we are all behind you at this sad time." A fourth said: "Nice to see their smiles after the past few days of mourning."
As per royal mourning guidelines, the royal couple appeared in black as a show of respect for the late Queen who passed away on 8 September. Kate donned a tailored black coat adorned with gold buttons which she paired with black heels.
The Queen's funeral was on Monday
Prince William, meanwhile, opted to wear a smart navy suit and black tie. Members of the royal family will continue to observe the royal mourning period until Monday 26.
The sweet visit comes after William and Kate were seen in attendance at the late Queen's funeral on Monday.
Despite how heartbreaking this time is for her family, the Queen has now been reunited with her beloved husband, Prince Philip, as well as her family, King George VI, the Queen Mother and Princess Margaret in the King George VI memorial chapel.
Make sure you never miss a ROYAL story! Sign up to our newsletter to get all of our celebrity and royal news delivered directly to your inbox.