Last month, reports claimed that Mayer had called time on his alleged romance with the Teenage Dream hitmaker after they were spotted 'holding hands' in Los Angeles.
It was later claimed that the singer/songwriter had dumped K-Pez over email after growing "tired of Perry's hard partying."
However, pictures have now emerged of the pair leaving LA restaurant The Little Door on Tuesday (4th September), with a friend of Katy's telling People: "They are seeing each other again."
Perry's pal then referenced her ex-hubby Russell Brand, stating: "The only thing that would surprise me is if she were to get back with Russell."
The 27-year old and Mayer were also seen together attending a FYF concert over the weekend, with E! Online reporting that the couple were dancing and kissing - with onlookers taking snaps of their PDA.
Watch MTV News on the hour every hour on MTV - Sky Channel 126 and Virgin Channel 134