The rebound is officially underway for Katy Perry ... who was all about the PDA with her new man at Coachella ... hugging, caressing and full on making out.
The guy is Robert Ackroyd -- the guitar player for Florence and The Machine.
The two were also spotted together at the music festival last weekend ... and according to some reports, Katy was already referring to him as her "boyfriend."
Guess she's finally ready to move on from her soon-to-be ex-husband Russell Brand -- who filed for divorce back in December.
As TMZ has previously reported, Brand and Perry have been on relatively good terms since the breakup ... with Brand refusing to make a play for any of the millions of dollars Perry raked in during their relationship.