UFC VP of public relations Dave Sholler confirmed the news via Twitter.
“He has indicated to UFC that he has retired. That should end the speculation for you,” Sholler said of Philippou in response to a message.
Philippou leaves the game with a respectable 13-5 (1 NC) record, but has lost three of his past four fights. The 35-year-old most recently dropped a unanimous decision to Gegard Mousasi in May.
Prior to his current skid, Philippou was making a legitimate run at a middleweight title tilt having won five straight. In fact, Philippou was so confident he was knocking on title contention that he left Serra-Longo Fight Team where reigning UFC 185-pound champion Chris Weidman trains.