The princess attended the launch and looked stunning in a white and blue floral print dress by Rebecca Vallance (£600).
The exhibition, led by Project Zero, is dedicated to raising awareness and funding for coral reefs, which are “one of the most critically endangered ecosystems on Earth”.
Eugenie said in a post featuring snaps of the auction on Instagram: “It was a joy to attend The Coral Collective’s charity art auction in support of coral preservation and restoration.
“Grateful to witness creativity being used as a force for ocean conservation & combining two of my greatest passions, art and the ocean [waves emoji[ #ForCoral #ForTheOcean @projectzero @coral_global.”
The “landmark” exhibition is taking place between June 12-20, at the Grand-Hôtel du Cap-Ferrat on the French Riviera.
It comes weeks after it emerged that Eugenie had taken on a new role linked to the King.
The princess will now also be mentoring a group of young creatives selected by the King’s Foundation as part of its new initiative to celebrate the charity’s 35th anniversary this year.
The 35 under 35 is a network of young people working with The King’s Foundation to promote the monarch’s legacy and ethos through their work in various industries, like environmental activism, fashion and architecture.
Eugenie has already met with a group of young creatives at the foundation’s base in the Garrison Chapel in Chelsea.