After it became clear that the first film would become a blockbuster success, a sequel was already in the works even before its release. However, Warner Bros. did not invite Village Roadshow Pictures, the first film's Australian production partner, to participate in the making of the sequel.
The film is set to be released on February 8, 2019 in 2D, 3D, RealD 3D, and IMAX 3D by Warner Bros. Pictures.
Even before the critical acclaim and blockbuster success of The Lego Movie, plans for a sequel had already been set in motion. On February 3, 2014, Jared Stern was hired to write the sequel, along with Michelle Morgan. On March 12, 2014, Deadline reported that animation co-director Chris McKay will direct the sequel with Lord and Miller as producers. Warner Bros. did not invite co-producer Village Roadshow Pictures to return as a participant in the sequel. On April 10, 2014, it was reported that McKay wanted to have more women in the sequel than men. On July 28, 2014, it was reported that Chris Pratt wants to return to reprise his role as Emmet. It was also reported that Will Arnett might return to reprise his role as Batman, but has not decided yet. However, he has reprised his role as Batman in The Lego Batman Movie.
In October 2014, Warner Bros. scheduled The Lego Batman Movie for 2017, and The Lego Movie 2 for 2018. On October 25, 2014, it was reported that Lord and Miller had signed on to write The Lego Movie 2. On October 30, it was announced that Australia-based animation studio Animal Logic was in talks to produce the next three Lego films (though the deal was not finalized at the time) and the New South Wales government would make financial contributions to all the films. On November 12, during an interview with BBC News, Lord and Miller revealed that there would be more female characters featuring in the film.
On February 24, 2015, the sequel was officially titled The Lego Movie Sequel and Rob Schrab was officially announced as the film's director, replacing McKay as director as he was scheduled to direct The Lego Batman Movie instead. By February 2017, Schrab had been replaced by Mike Mitchell, reportedly due to "creative differences".