Also in attendance for closing night was Perry's 3-year-old daughter, Daisy Dove, who she shares with fiancé Orlando Bloom.
Katy Perry closed out her Las Vegas residency on Saturday night in style and in good company as audience members for her final show consisted of names like Céline Dion, Prince Harry and Meghan Markle.
Over the weekend, Perry, 39, took to the stage one last time to perform hits for her fans including songs like "California Girls," "Hot N Cold," "Roar" and "Firework" during her Play residency at Resorts World which began in December 2021.
Eagle-eyed fans spotted the Duke and Duchess of Sussex in the building Saturday and one fan even captured a video of the couple -- who stepped back from their royal duties in March 2020 -- sitting alongside Perry's fiancé Orlando Bloom.
Prince Harry, 39, could be seen staring intently at the stage alongside Bloom, 46, while Meghan, 42, danced to the music from one row behind.
In another photo, Prince Harry and Meghan could be seen following Dion, 55, while security guards and onlookers crowded around the trio.
One fan managed to snap a photo with the "My Heart Will Go On" singer at one point during the night and wrote on social media platform X -- formerly known as Twitter -- that they had the chance to talk with her, calling it the "best moment" of their life while sharing a selfie with Dion.
Dion's surprise appearance at Perry's last show is one of her first public appearances since she was diagnosed with Stiff-Person Syndrome in 2022. According to the Cleveland Clinic, only about one out of every one million people are diagnosed each year with the neurological syndrome that causes muscle stiffness and painful muscle spasms.
Earlier this week, Dion also appeared at an NHL game between the Vegas Golden Knights and the Montreal Canadiens at T-Mobile Arena alongside her three sons.
Also in attendance Saturday night was Perry's 3-year-old daughter, Daisy Dove, who she shares with Bloom.
The "Waking Up In Vegas" singer gave her daughter a special shout-out and thanked her "best friend" for coming to the show, which marked Daisy's first-ever public appearance.
"Daisy! I love you so much," Perry said while on stage in a video posted to X, formerly known as Twitter. "You're my best friend, I'm so glad you're here."
Bloom and Perry got engaged on Valentine's Day in 2019 and welcomed Daisy in August 2020.
In 2022, the singer sat down with Drew Barrymore on her eponymous show and talked about their upcoming nuptials, telling the host that they were looking to set a date and location "soon."
"There's still a plan but the location is challenging," Perry said. "I love a big celebration. I am all about big, fun, exotic, great celebrations. So, hopefully, soon."