Nicky Hilton got engaged to James Rothschild early last month.
The 30-year-old proudly flashes her giant engagement ring in an Instagram snap posted on Friday.
The Eiffel Tower and the Seine are visible in the background.
"#engagementmoom in Paris. #FlashbackFriday", she captioned the picture.
The fashion designer and heiress, who has been in a relationship with the banker since meeting at Petra Ecclestone and James Stunt's Italy wedding in 2011, is 'incredibly happy' after he proposed to her in Lake Como in August.
A source close to the couple told UsMagazine.com: "They went on a romantic anniversary trip over the weekend. He took her out on a boat into the middle of Lake Como and he proposed, got down on one knee and everything. It was incredibly romantic and beautiful."