The 26-year-old has apologised to fans for cancelling shows in Chicago, Illinois, today and in St Paul, Minnesota, tomorrow.
Both gigs have been re-scheduled for August.
The Teenage Dream hitmaker reportedly had to pull the concerts because of 'an attack of food poisoning leading to severe dehydration', according to Jam Productions.
She tweeted today: 'Chicago and St Paul - I'm so sorry to have to postpone today and tomorrow's shows. But I'll be back 8/21 (Chi) and 8/23 (St Paul)!'
In a message on her official website, Perry added: 'I apologise to my fans in Chicago and the Twin Cities for not being able to perform this weekend, but I am going to return in a few weeks to give them the very best show ever!'