Camilla was on hand to reopen the Palace as part of her role as Honorary Patron of the Fulham Palace Trust, Hello! Magazine reports.
Later on Wednesday, the busy royal headed to Marlborough House in London to attend the first Garden Party for 'Bees for Development', where she tried some Indian honey and even had a go at Ugandan basket weaving!
Last weekend, Camilla joined senior members of the royal family to celebrate Queen Elizabeth II's official 93rd birthday at the Trooping the Colour parade in London.
With the Prince of Wales engaged in military duties, the Duchess arrived at Buckingham Palace in a carriage with Kate, Duchess of Cambridge, Prince Harry and Meghan, Duchess of Sussex.
The Queen's annual event marked new mum Meghan's first public appearance since introducing her newborn royal baby Archie Harrison to the world with a photocall at St George's Hall in Windsor last month.
On the balcony of Buckingham Palace the royal foursome were joined by Prince Andrew, Princess Anne, Prince Michael of Kent, Prince William and his three children with Kate Middleton, Prince George, Princess Charlotte and Prince Louis who stole the show with his adorable antics and cheeky wave.
One-year-old Louis, who was making his balcony debut, almost knocked his step-grandmother hat off during the RAF flypast, much to Camilla's delight.
Camilla once told Daily Mail: "My own grandchildren call me GaGa. I don't know if that's because they think I am! It is funny but it's still very sweet."
Earlier this month, Prince Charles and Camilla were front and centre representing the royal family during President Donald Trump's state visit to Britain.
The Duchess of Cornwall shocked (and delighted) fans when she was caught on camera delivering a sneaky wink to officials after President Trump and First Lady Melania joined the royal couple for tea at Clarence House.
The gesture - which was captured by Sky News - prompted one commentator to remark: "Camilla's wink is probably the best thing about this visit so far."