Clinton, 69, presented the "Roar" singer, 32, with the Audrey Hepburn Humanitarian Award for her charitable work. The former secretary of state — who lost the presidential election to Republican rival Donald Trump on November 8 — received a huge round of applause when she made her way on stage.
Perry, for her part, appeared emotional as she took photos with Clinton. The pop star heavily campaigned for the politician and performed at the Democratic National Convention in Philadelphia in July.
This time, it was Clinton's chance to support Perry. "I have seen Katy's commitment to the causes she believes in firsthand," Clinton said. "I've gotten to spend time with her and I know how deeply she cares about making our world a better place. She is serious about understanding the complex problems we face and pulling people together to solve them. We need champions like Katy now more than ever: her passion, her energy and, yes, her voice, louder than a lion."
Perry, who has been a UNICEF Goodwill Ambassador since 2013, joked that she needed a tissue after Clinton's speech. "I've always had a voice — a singing voice — but I've never had a voice like I've had before. Hillary has lit that voice inside of me, and that light will never go out, it will continue to get brighter and brighter and brighter," Perry said. "Thank you, Hillary. You motivate me and so many millions of people. We appreciate you for your incredible work and your heart."
Can't get enough of Us? Sign up now for the Us Weekly newsletter packed with the latest celeb news, hot pics and more!