Philip Treacy's headpiece worn by Princess Beatrice at the royal wedding sold for £81,000 on eBay.
Around 40 bidders competed in the auction to win the hat, which sparked controversy among fashionistas following Kate and William's wedding.
The headwear creation had its own Facebook page, attracting thousands of followers who commented on the hat, which some compared to a pretzel or toilet seat.
Undeterred, the 22-year-old princess decided to sell off the item for charity, with Unicef and Children in Crisis to benefit from the funds raised.
She commented on the auction page: 'I've been amazed by the amount of attention the hat has attracted. It's a wonderful opportunity to raise as much money as possible for two fantastic charities. 'I hope whoever wins the auction has as much fun with the hat as I have.'
The description on the auction site calls the pale pink silk hat a 'unique sculptural celebratory headpiece'.
Images: Princess Beatrice, Philip Treacy hat