Jackson made his announcement after media reports Thursday that none of the judges -- including Jackson, Keith Urban, Mariah Carey and Nicki Minaj -- would be back for Season 13.
"Yo! Yo! Yo! To put all of the speculation to rest, after 12 years of judging on 'American Idol' I have decided it is time to leave after this season," Jackson said in a statement.
"I am very proud of how we forever changed television and the music industry. It's been a life changing opportunity but I am looking forward to focusing on my company Dream Merchant 21 and other business ventures."
Jackson is the only original judge left on "Idol."