"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 has been with the show for all 12 of its seasons, since it first premiered as American Idol: The Search for a Superstar in 2002.
His departure marks the end of an era for Idol, as has been the only original judge to remain with the show for its duration, as fellow initial judges Paul Abdul and Simon Cowell left after the show's eighth and ninth seasons, respectively.
The 56-year-old bassist and producer's exit comes after a ratings slip for the singing show, which some have attributed to the lack of chemistry at the judges' table, particularly between feuding foes Nicki Minaj and Mariah Carey.
Jackson, who co-produced the talent show America's Best Dance Crew, made no declaration of any specific plans in television.