She was partying until the early hours of Thursday morning following the BRIT Awards.
However, Katy Perry certainly didn't show any signs of being hungover as she made a cameo appearance at the catwalk at Milan Fashion Week.
The pop star jetted from London to Italy to be in the front row to toast her friend Jeremy Scott's debut collection for Moschino.
The famous pop queen ended up walking down the catwalk to get to her front row seat - creating somewhat of a mini fashion show for photographers before the main event.
She appeared to be wearing clothes from Jeremy's Autumn/Winter 2014 collection. Katy, 29, opted for a black satin dress and coat.
Fashion critics complained the show started 45 minutes late, with many suggesting
the level of slayage is unreal