The 32-year-old singer shared a BTS video of her experience during the benefit concert that took place at the Old Trafford Stadium in Manchester, England, on June 4.
The show was held to benefit the victims and families involved in the terror attack at Grande's concert in Manchester last month that left 22 people dead and over 100 injured.
In the video, Katy is seen rehearsing for the show, greeting Coldplay's Chris Martin, Justin Bieber, Miley Cyrus and taking pics with Niall Horan. The singer also does an interview right before taking the stage.
The "Swish Swish" singer performed an acoustic rendition of her hit "Part of Me," followed by her empowering single, "Roar." She also paid tribute to the victims with her outfit, which featured actual photos of those affected by the tragic bombing.
For more on the One Love Manchester concert, watch below.