The 53-year-old had quit the panel to work on his US version of the programme, reported Daily Mirror.
Last year, X-Factor UK series saw a slump in viewership and bosses are considering ways to rekindle public interest.
"I'm definitely getting more involved. I'm not going to lie. I do miss doing it, because it's, like, my baby. So at some point of course I'm going to come back," Cowell said.
He returns to small screen with a new series of Britain's Got Talent beginning next month.