Cowell's comments follow Harry's nude photo scandal in which he was caught partying with a bevy of beauties in a Las Vegas hotel suite.
Someone photographed him completely nude during a game of strip billiards and sold them to a US website, reported Contactmusic.
But Cowell feels it is nothing abnormal.
"He's one heck of a nice guy and if I was his age I would have ended up with a few cute girls in a hotel room with my clothes off too," Cowell said.