In the UK, ratings have faltered with audiences down on recent years and on Saturday the show found itself more than a million viewers behind BBC1's Strictly Come Dancing for a second consecutive week.
Cowell said he "couldn't be happier" about the newly commissioned series.
"I am so proud of the show and the team who have made it this season.
"Our main commitment will always be to find great talent, and let's not forget, we are now days away from our first live shows. The gloves are off. Expect fireworks."
Cowell left the UK version of the show after its 2010 run to launch the US series.