The "Dark Horse" singer shared the snapshot on Instagram under the caption: "...And on the 2nd LDN show the Queen graced me with her presence"
Perry's Prismatic Tour has four scheduled shows in London, the last one will take place on May 31. The singer will then take a short break before resuming the tour in America.
Perry's first performance in the U.S. will take place in Raleigh's PNC Arena on June 22.
Notable deaths of 2014 [PHOTOS]