The film was announced in October 2014 with Snyder on board to direct and Terrio attached to write the script. Principal photography commenced on April 11, 2016 and ended on October 14, 2016. Snyder left the film on May 22, 2017, following the suicide of his daughter; Joss Whedon was brought on to finish reshoots and the post-production process. Justice League is scheduled to be released on November 17, 2017, in 2D, 3D and IMAX 3D.
The benefactor of the group of metahumans who is also a billionaire socialite and CEO of Wayne Enterprises who dedicates himself to protecting Gotham City from its criminal underworld as a highly trained, masked vigilante equipped with many powerful tools and weapons.
A Kryptonian survivor and journalist for the Daily Planet with superhuman abilities who seemingly died after the events of Batman v Superman: Dawn of Justice. On February 5, 2016, Cavill announced on social media that he had already started exercising for the film in advance of principal photography.
An antiquities dealer and acquaintance of Wayne who is actually a 5,000 year-old immortal Amazonian warrior princess from Themyscira and daughter of Zeus, who possesses superhuman attributes and abilities inherited from her parents.
A former college athlete who, after being cybernetically reconstructed with a Mother Box after a nearly fatal accident, has powers that allow him to manipulate technology and to turn his arms to cannons. Fisher portrays the character through the assistance of motion capture performance, for the cybernetic portion of his body.
A general of the New Gods of the planet Apokolips who is charged with hunting down the three Mother Boxes on Earth for his nephew and commanding officer Darkseid. The character had previously appeared in the extended Ultimate Edition of Batman v Superman: Dawn of Justice, in which he communicates with Lex Luthor through Kryptonian hologram technology. In March 2017, Ciarán stated that Steppenwolf is old, tired and trying to get out of his enslaved position under Darkseid. Hinds will portray the villain through use of motion capture performance and received help in that process from his friend Liam Neeson, who had recently done similar work in A Monster Calls.
In February 2007, it was announced that Warner Bros. hired husband and wife duo Michele and Kieran Mulroney to write a script for a Justice League film. The news came around the same time that Joss Whedon's long-developed Wonder Woman film had been cancelled, as well as The Flash, written and directed by David S. Goyer. Reportedly titled Justice League: Mortal, Michele and Kiernan Mulroney submitted their script to Warner Bros. in June 2007, receiving positive feedback, which prompted the studio to immediately fast track production in the hopes of filming to begin before the 2007-2008 Writers Guild of America strike. Warner Bros. was less willing to proceed with development with a sequel to Superman Returns, having been disappointed with the box office return. Brandon Routh was not approached to reprise the role of Superman in Justice League: Mortal, nor was Christian Bale from Batman Begins. Warner Bros. intended for Justice League: Mortal to be the start of a new film franchise, and to branch out into separate sequels and spin-offs. Shortly after filming finished with The Dark Knight, Bale stated in an interview that "It'd be better if it doesn't tread on the toes of what our Batman series is doing," though he personally felt it would make more sense for Warner Bros. to release the film after The Dark Knight Rises.Jason Reitman was the original choice to direct Justice League, but he turned it down, as he considers himself an independent filmmaker and prefers to stay out of big budget superhero films.George Miller signed to direct in September 2007, with Barrie Osbourne producing on a projected $220 million budget.
However, the Writers Strike began that same month and placed the film on hold. Warner Bros. had to let the options lapse for the cast, but development was fast tracked once more in February 2008 when the strike ended. Warner Bros. and Miller wanted to start filming immediately, but production was pushed back three months. Originally, the majority of Justice League: Mortal would be shot at Fox Studios Australia in Sydney, with other locations scouted nearby at local colleges, and Sydney Heads doubling for Happy Harbor. The Australian Film Commission had a say with casting choices, giving way for George Miller to cast Gale, Palmer and Keays-Bryne, all Australian natives. The production crew was composed entirely of Australians, but the Australian government denied Warner Bros. a 40 percent tax rebate as they felt they had not hired enough Australian actors. Miller was frustrated, stating that "A once-in-a-lifetime opportunity for the Australian film industry is being frittered away because of very lazy thinking. They're throwing away hundreds of millions of dollars of investment that the rest of the world is competing for and, much more significantly, highly skilled creative jobs." Production offices were then moved to Vancouver Film Studios in Canada. Filming was pushed back to July 2008, while Warner Bros was still confident they could release the film for a summer 2009 release.
With production delays continuing, and the success of The Dark Knight in July 2008, Warner Bros. decided to focus on the development of individual films featuring the main heroes, allowing director Christopher Nolan to separately complete his Batman trilogy with The Dark Knight Rises in 2012. Gregory Noveck, senior vice president of creative affairs for DC Entertainment stated "we're going to make a Justice League movie, whether it's now or 10 years from now. But we're not going to do it and Warners is not going to do it until we know it's right." Actor Adam Brody joked "They [Warner Brothers] just didn't want to cross their streams with a whole bunch of Batmans in the universe." Warner Bros. relaunched development for the solo Green Lantern film, released in 2011 as a critical and financial disappointment. Meanwhile, film adaptations for The Flash and Wonder Woman continued to languish in development while filming for a Superman reboot was commencing in 2011 with Man of Steel, produced by Nolan and written by Batman screenwriter David S. Goyer. Shortly after filming had finished for Man of Steel, Warner Bros hired Will Beall to write the script for a new Justice League film. Warner Bros. president Jeff Robinov explained that Man of Steel would be "setting the tone for what the movies are going to be like going forward. In that, it's definitely a first step." The film included references to the existence of other superheroes in the DC Universe, and setting the tone for a shared fictional universe of DC Comics characters on film. Goyer stated that should Green Lantern appear in a future installment, it would be a rebooted version of the character and not connected to the 2011 film. With the release of Man of Steel in June 2013, Goyer was hired to write a sequel, as well as a new Justice League, with the Beall draft being scrapped. The sequel was later revealed to be Batman v Superman: Dawn of Justice, a team up film featuring Ben Affleck as Batman, Gal Gadot as Wonder Woman, and Ray Fisher as Victor Stone / Cyborg in a minor role that will become more significant in leading up to the proposed Justice League film. The universe is separate from Nolan and Goyer's work on The Dark Knight trilogy, although Nolan is still involved as an executive producer for Batman v Superman. In April 2014, it was announced that Zack Snyder would also be directing Goyer's Justice League script. Warner Bros. was reportedly courting Chris Terrio to rewrite Justice League the following July, after having been impressed with his rewrite of Batman v Superman: Dawn of Justice. On October 15, 2014, Warner Bros. announced the film would be released in two parts, with Part One releasing on November 17, 2017, and Part Two on June 14, 2019. Snyder will direct both films. In early July 2015, EW revealed that the script for Justice League Part One had been completed by Terrio. Zack Snyder stated that the film will be inspired by the New Gods comic series by Jack Kirby. Although Justice League was initially announced as a two-part film with the second part releasing two years after the first, Snyder announced in June 2016 that they would be two distinct, separate films and not one film split into two parts, both being stand-alone stories.
In April 2014, Ray Fisher was cast as Victor Stone / Cyborg, and was set to cameo in Batman v Superman: Dawn of Justice followed by a larger role in Justice League. Henry Cavill, Ben Affleck, Gal Gadot, Diane Lane and Amy Adams are also expected to reprise their roles from Batman v Superman: Dawn of Justice. In October 2014, Jason Momoa was cast as Arthur Curry / Aquaman and debuted as the character in Dawn of Justice. On October 20, 2014, Momoa told ComicBook.com that the Justice League film would be coming first and that is what they were preparing for, and he did not know if the solo Aquaman film would be prior to Justice League or post. He thought it might be the origin of where Aquaman came from. On January 13, 2016, The Hollywood Reporter announced that Amber Heard was in negotiations to appear in the film as Aquaman's love interest Mera. In March 2016, producer Charles Roven said that Green Lantern would not appear in any film before Justice League Part Two, and stated that they "could put Green Lantern in some introduction in Justice League 2, or barring that, a movie after." Also in March, The Hollywood Reporter announced that J. K. Simmons was cast as Commissioner James Gordon, and Heard was confirmed to join the cast as Mera. Adams also confirmed that she would reprise her role as Lois Lane in both Justice League films. The following month, Simmons confirmed that he would play Gordon. By April 2016, Willem Dafoe was cast in an undisclosed role, later revealed to be Nuidis Vulko. Cavill confirmed that he would return for both Justice League films. In May 2016, Jeremy Irons confirmed he will appear as Alfred Pennyworth. That same month, Jesse Eisenberg stated that he would reprise his role as Lex Luthor, and in June 2016, he confirmed in an interview with Shortlist magazine of his return. In July 2016, Julian Lewis Jones was cast in an undisclosed role.Laurence Fishburne, who portrays Perry White in the DCEU, said he declined to reprise his role in this film due to scheduling conflicts. In April 2017 , Michael McElhatton revealed that he has a role in the film.
In July 2015, it was revealed that filming would begin in spring 2016 after Wonder Woman ended principal photography. Principal photography commenced on April 11, 2016, with shooting taking place at Warner Bros. Studios, Leavesden, as well as various locations around London, Scotland, Los Angeles and in Djúpavík in the Westfjords  of Iceland. Snyder's longtime cinematographer Larry Fong was replaced by Fabian Wagner due to scheduling conflicts. Affleck was also revealed to be serving as executive producer. In May 2016, it was revealed that Geoff Johns and Jon Berg will be producing the Justice League films and they will also be in charge of the DC Extended Universe after the largely negative critical reception of Batman v Superman: Dawn of Justice. Geoff Johns confirmed on June 3, 2016, that the title of the film is Justice League. That same month, Irons stated that the Justice League storyline will be more linear and simple, in comparison to the theatrical version of Batman v Superman: Dawn of Justice. Johns later stated that the film would be "hopeful and optimistic" in comparison to the previous DCEU films. Momoa confirmed via Instagram that principal photography ended in London on October 1, 2016. On October 7, 2016, Zack Snyder confirmed via Twitter that filming wrapped in the United Kingdom. On October 14, Momoa confirmed via Instagram that filming wrapped in Iceland.
In May 2017, Snyder stepped down from directing the film to properly deal with the death of his daughter. Joss Whedon, who Snyder had previously brought on to rewrite some additional scenes, was hired to direct re-shoots for the film and handle post-production duties in Snyder's place.
In March 2016, Hans Zimmer, who composed the score for Man of Steel and Batman v Superman: Dawn of Justice, stated that he is officially retired from the "superhero business". By June 2016 he was replaced by Junkie XL, who wrote and composed the soundtrack of Dawn of Justice alongside Zimmer himself.
A sequel was scheduled to be released on June 14, 2019, but has since been delayed to accommodate the release for a standalone Batman film. In March 2017, producer Charles Roven announced that Zack Snyder will return as director.