The judges are to replace LA Reid and Britney Spears, both of whom quit the show at the end of season two.
Writing on Twitter, Cowell revealed that the X Factor USA auditions begin in Charleston on Tuesday (May 21), with the new panel being announced the previous day.
We start x factor auditions in charleston on Tuesday. The new panel will be announced Monday. This is going to be an interesting show!— Simon Cowell (@SimonCowell) May 18, 2013
Kelly Rowland, Jennifer Love Hewitt, Cheryl Cole and Katy Perry are among the stars rumoured to be replacing Reid and Spears.
Demi Lovato and Cowell will be the only judges to return to the competition for the third season.
Mario Lopez will be back as the sole host after show bosses decided to ditch Khloe Kardashian.
Lovato has previously said that she wants Britney Spears back on the programme.