Simon was talking about the upcoming first season of his latest TV contest during an interview with Jay Leno this week, when he ruled-out hiring Diddy as the rapper is "too expensive".
Simon Cowell says P Diddy and Christina Aguilera won't be given jobs as judges on the American X Factor.
When asked about Burlesque star Christina, Cowell told the talk show host, "Absolutely not". (Rude.)
Another name mentioned by Leno is R&B singer Usher, to which he replied: "Maybe. Yeah I like Usher. He's good," before mentioning Paula Abdul and joking about hiring actor Charlie Sheen.
And despite Simon saying he'd already spoken with Shania Twain and Jessica Simpson about becoming judges, he's still unsure who to hire for the job.
"I can't make up my mind. I've been meeting all these people every day and I like them and at the moment I could end up with about 23 judges on this panel. One contestant, 23 judges!"