The Skyscraper singer will wrap up her second season on the talent competition's judging panel, alongside Simon Cowell, Kelly Rowland and Paulina Rubio, following its two-part finale this week (18&19Dec13) - and she won't be back.
A source tells People.com, "She plans to spend next year completely focused on her music. She had a great run and a good time."
Lovato will embark on her first arena tour in February (14), and will be joined by The X Factor alums Cher Lloyd, Little Mix and Fifth Harmony for the trek.
Show creator Cowell has announced The X Factor will return to Tv screens for its fourth season in 2014, although it is not yet known whether he, Rowland or Rubio will be heading back as judges.