The Lego Ninjago Movie is a 2017 animated martial arts comedy film, based on the toy/kit line of the same name and the TV show starring the same characters. It was directed by Charlie Bean, Paul Fisher, and Bob Logan (in their feature directorial debuts) from a screenplay by Logan, Fisher, William Wheeler, Tom Wheeler, Jared Stern, and John Whittington. It is the first theatrical film to be based on an original Lego property and the third installment in The Lego Movie franchise as well as its second spin-off. The film stars the voices of Dave Franco, Michael Pena, Kumail Nanjiani, Abbi Jacobson, Zach Woods, Fred Armisen, Justin Theroux and Olivia Munn, as well as a live-action role by Jackie Chan (who also voiced Wu in the film). The film focuses on a teenage ninja Lloyd Garmadon, as he attempts to accept the truth about his sinister father and learn what it truly means to be a ninja warrior as a new threat emerges to endanger his homeland.

An animated feature film based on Ninjago was announced in September 2013 by Warner Bros., with The Hageman Brothers writing the adaptation while Bean was hired to direct the film with Phil Lord and Christopher Miller, Dan Lin and Roy Lee producing. By May 2014, following the success of The Lego Movie, Warner Bros. announced that the film would be originally released in September 2016, which later changed to September 2017 in April 2015. The cast were signed in to voice the characters in 2016, from June to August. As with The Lego Movie and The Lego Batman Movie, the animation was provided by Animal Logic. Mark Mothersbaugh, who composed The Lego Movie, composed the film's musical score, with several artists performing new original songs for the film.

A collaboration between production houses from the United States and Denmark, The Lego Ninjago Movie was released by Warner Bros. Pictures in the United States on 22 September 2017. The film received mixed reviews from critics and was the franchise's first box-office disappointment, grossing only $123.1 million worldwide against its $70 million budget. A live-action reboot from Universal Pictures is in development.