Perry popped in following Afrojack at the live streaming dance festival, hosting a lineup including Martin Garrix, Steve Aoki, David Guetta and more this weekend.
Backed by an elaborate virtual set, she performed a feel-good medley that kicked off with "Smile" from a clown face hot air balloon.
"Hello Tomorrowland! I'm Katy Perry and I hope you can smile with me tonight," she called out to the crowd at home.
The performance continued with bits of hits like "Teenage Dream," "California Gurls," "Dark Horse" and "Roar," all on the virtual fantasyland stage with her band covered in Mad Hatter-like top hats.
Perry brought to life her "Daisies (Can't Cancel Pride)" remix accompanied by a giant virtual daisy that danced and smiled. The mix works in pieces of Perry's back catalog, including "I Kissed a Girl" and "I'm Walking on Air."
She wrapped things with "Firework" as circus-ready balloons were suspended in the air above the virtual crowd, and virtual fireworks filled the sky
See Perry's selfies from getting ready for the special gig and a clip of her "Smile" opening below, and tune in to Tomorrowland with a single or two-day pass as it goes on Saturday night and Sunday.