There were reports that the 45-year-old songstress had been involved with the "Rush Hour" director since her split from Nick Cannon.
Ratner's representative said any report claiming Carey and Ratner are dating is "ridiculous."
"They have been best friends for a very long time," the rep said.
Ratner has been the director of Carey's eight music videos including "Heartbreaker", "I Still Believe" and "We Belong Together".
Carey split from former husband Cannon in 2014. The "America's Got Talent" host has since moved on with Jessica White.