His tweet came after a few tabloid reports claimed that the actor and pop star were spotted getting cozy at Elton John's birthday bash.
Phillippe, 42, slammed the reports, saying that he "barely knows" the 32-year-old songstress.
"I AM NOT DATING KATY PERRY. BARELY KNOW HER. PLEASE STOP FLYING HELICOPTERS OVER MY HOUSE. SHE IS NOT HERE," he tweeted in all caps.