Eugenie posted the photo during her visit with the caption: "I co-founded @the_anti_slavery_collective to bring together change-makers to raise awareness for modern slavery as a global epidemic."
The royal continued: "Today I met an incredible organisation, @stopthetraffik, who are empowering people to take action against #humantrafficking. Their intelligence-led STOP APP is the only one of its kind to combine community empowerment, big data management and anti-trafficking expertise to disrupt this horrific crime. #enditmovement."
Fans were quick to praise Eugenie for her philanthropy, with many on social media users dubbing the Queen's grandaughter a 'real' princess.
One fan commented on the photo: "We love you, keep showing what a real princess does, this generation will change the world."
Another social media user commented: "Keep up the good work, Madam! Fighting against human trafficking is one of the most needed objectives these days. I also appreciate how each member of the British Royal Family represents a good cause!"
Princess Eugenie, 28, co-founded The Anti-Slavery Collective with one of her best friends, Julia de Boinville. Their mission is the raise awareness for modern slavery as a global epidemic.