In February 2014, it was reported that Warner Bros. had started working on a sequel, with Jared Stern and Michelle Morgan tasked to write a screenplay. On February 21, 2014, the studio scheduled the sequel for a May 26, 2017 release. On March 12, 2014, Deadline reported that animation co-director Chris McKay would direct the sequel with Lord and Miller as producers. Warner Bros. did not invite co-producer of the first film, Village Roadshow Pictures, to return as a participant in the sequel, due to Warner Bros. having now more confidence in the film and trying to keep as much profit as possible for itself. On April 10, 2014, McKay expressed that he would like to introduce more women in the sequel than men. In July 2014, it was reported that Chris Pratt expressed interest in reprising his role as Emmett for the sequel.
In October 2014, Warner Bros. scheduled The Lego Batman Movie for 2017, and The Lego Movie 2 for 2018. By October 25, 2014, Lord and Miller had signed on to write The Lego Movie 2. The writers have implied that the sequel will take place four years after the events of the first film. In February 2015, Warner Bros. announced that the title of the sequel had been changed to The Lego Movie Sequel, and that Rob Schrab, co-writer of Monster House replaced McKay as director since McKay went to direct The Lego Batman Movie. According to an interview at the Santa Barbara Film Festival, the sequel will focus on Emmet and his sister, taking place in "weird, dystopian version of Bricksburg." On April 20, 2015, Warner Bros. scheduled The Lego Movie Sequel for a May 18, 2018 release date. On June 17, 2016, the film's release was delayed to February 8, 2019. By July 2016, Raphael Bob-Waksberg had been hired to do rewrites of the script. By February 2017, Schrab had been replaced by Mike Mitchell, reportedly due to "creative differences".
In October 2014, Warner Bros. scheduled The Lego Batman Movie, a spin-off starring Batman for 2017, which moved The Lego Movie Sequel to 2018. Will Arnett returned to voice Batman, while Chris McKay, who was earlier attached to the sequel, will direct the film which is being written by Seth Grahame-Smith and produced by Roy Lee, Dan Lin, Phil Lord and Chris Miller. On April 20, 2015, Warner Bros. scheduled The Lego Batman Movie for a February 10, 2017 release. In July 2015, Arnett's Arrested Development co-star Michael Cera was cast to voice Robin. In August 2015, Zach Galifianakis entered final negotiations to voice the Joker. In October 2015, Rosario Dawson was cast to voice Barbara Gordon, the daughter of police commissioner James Gordon who later becomes the crime-fighting heroine Batgirl. The following month, Ralph Fiennes was cast as Alfred Pennyworth, Bruce Wayne's butler. Mariah Carey, although initial reports indicated she was playing Commissioner Gordon, was actually cast as Mayor McCaskhill. The first trailer for the film was released on March 24, 2016, followed by a second on March 28 the same year. The film was released in the United States on February 10, 2017.
In March 2015, Warner Bros. announced that a third Lego Movie spin-off, titled The Billion Brick Race, was in development. Jason Segel and Drew Pearce were signed on to co-direct and write the film. The film is scheduled to be released on May 24, 2019.
On December 16, 2015, a promo video for a new "4D" film at Legoland Florida based on The Lego Movie called The Lego Movie: 4D - A New Adventure was posted onto Lego's YouTube channel. The short subject premiered at Legoland Florida on January 29, 2016 before being rolled out to all other Legoland Parks and Legoland Discovery Centers later that year. It sees many of the original cast returning including Elizabeth Banks, Nick Offerman, Alison Brie, and Charlie Day while Emmett is voiced by A.J. Locascio (due to Chris Pratt being unavailable at the time). The film is titled The Lego Movie 4D: A New Adventure, and introduces a new character called Risky Business (voiced by Patton Oswalt) who is Lord Business' older brother.