The `Promise This` singer - who has won the past two consecutive seasons of the UK show with her acts Alexandra Burke and Joe McElderry - will join Simon Cowell on the Stateside judging panel after impressing show bosses with her "good looks" and natural "chemistry" with the music mogul.
An insider told The Sun newspaper: "It`s a dream come true. Cheryl was absolutely delighted. She has really charged the American execs. They love her good looks and the way she wears her heart on her sleeve.
"And of course her chemistry with Simon played a huge part in it. They are great together."
Fox bosses jetted to London on Saturday night (27.11.10) to see the 27-year-old star in action as her remaining acts Rebecca Ferguson, Cher Lloyd and Katie Waissel - who was eliminated from the competition on Sunday - battled it out in the UK pop star search show.
While Cheryl is yet to sign the official contract, filming for the US `X Factor` is due to begin in the spring with the series broadcast in the run-up to Christmas 2011.
Meanwhile, Pussycat Dolls singer Nicole Scherzinger - who appeared on the UK show as a guest judge earlier in the year - is also believed to be in the running to join the line-up.
Simon is expected to make an official announcement within the next month.
He recently said: "I`m going to make an announcement within three or four weeks, which is going to tell everyone everything. There will be some surprises. OK, one of the judges has quite long hair."