Directed by Zack Snyder, who was replaced by Joss Whedon after Snyder left the project, and written by Chris Terrio and Whedon, the film features an ensemble cast including Ben Affleck, Henry Cavill, Gal Gadot, Ezra Miller, Jason Momoa, Ray Fisher, Amy Adams, Jeremy Irons, Diane Lane, Connie Nielsen, and J. K. Simmons.

Warner Bros. began to develop a live-action Justice League film in 2007 with George Miller set to direct, but the project was canceled due to production delays and budgetary concerns.

Knowing this information, Wayne decides to use the Mother Box to resurrect Superman, not only to help them fight off Steppenwolf's invasion but also to restore hope to humanity.

Clark Kent's body is exhumed and placed in the amniotic fluid of the genesis chamber in the Kryptonian scout ship, along with the Mother Box, successfully resurrecting him.

Diana and Arthur resume their heroic duties; Barry acquires a job in Central City's police department; Victor continues to enhance his abilities with his father in S.T.A.R.

[20][21][non-primary source needed] All three were required to reach a specific degree of physicality, with Snyder instructing McKinless to sport "veins like worms and paper thin skin".

Joe Manganiello and Jesse Eisenberg appear uncredited in a post-credits scene as Slade Wilson / Deathstroke and Lex Luthor, respectively.

In February 2007, it was announced that Warner Bros. Pictures had hired husband-and-wife duo Michele and Kieran Mulroney to write a script for a Justice League film.

[40] Reportedly titled Justice League: Mortal,[41] the script by Michele and Kieran Mulroney was submitted to Warner Bros. in June 2007, receiving positive feedback,[42] which prompted the studio to immediately fast track production in the hope of beginning filming before the 2007–08 Writers Guild of America strike.

[45] 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.

[50] The following month, roughly 40 actors and actresses auditioned for the ensemble superhero roles, among them Joseph Cross, Michael Angarano, Max Thieriot, Minka Kelly, Adrianne Palicki, and Scott Porter.

[56] Hip hop recording artist and rapper Common was cast,[57] with Adam Brody as Barry Allen / Flash,[58] and Jay Baruchel as the lead villain, Maxwell Lord.

In October 2012, following its legal victory over Joe Shuster's estate for the rights to Superman, Warner Bros. announced that it planned to move ahead with the Justice League film.

Though the universe of Man of Steel was separate from that of Nolan's The Dark Knight trilogy, he was still involved as an executive producer on both Batman v Superman and the Justice League film.

It was reported that Warner Bros. held a footage summit for writers that include Whedon, Wonder Woman screenwriter Allan Heinberg, Seth Grahame-Smith, and Andrea Berloff.

[96][97][98] In May 2017, Snyder stepped down from directorial duties on Justice League to cope with his daughter Autumn's suicide, and Whedon assumed his position to oversee post-production and complete the film.

Paramount executives eventually intervened and refused permission altogether, necessitating the mustache to be digitally removed for Justice League.

Speaking at the Calgary Comic and Entertainment Expo, Lee stated "that [Snyder] was not fired at all and that he stepped down from the production due to a family matter", as far as he knew.

[114] In July 2020, Ray Fisher claimed that Whedon's on-set treatment of the film's cast and crew was "gross, abusive, unprofessional, and completely unacceptable".

[115] Justice League and Batman v Superman writer Chris Terrio called the theatrical cut an act of vandalism, and attempted unsuccessfully to get his name removed from the film.

Junkie XL, who wrote and composed the soundtrack of Batman v Superman: Dawn of Justice with Zimmer, was originally scoring the film,[118] but was replaced by Danny Elfman the following year in June.

[123] Superman was intentionally left out on all early Justice League marketing materials, including trailers, clips, and posters, which actor Cavill commented as "ridiculous".

[149][150] In 2018, Forbes compared the drastic incohesive shift from Snyder's darker films Man of Steel and Batman v Superman: Dawn of Justice to the lighter Justice League (co-written by Whedon), to the similarly drastic and incohesive change in tone experienced from the older 1989 and 1992 Tim Burton's Batman films to the direct light-hearted sequels directed by Schumacher, although noting the former shift in tone was better received than the one in Justice League, affecting box office, due to going against the expectations of Snyder fans in its attempt to reach a higher demographic, while alienating its own established core audience.

[154] Justice League received mixed reviews, which praised the chemistry of the cast and the direction, but compared it unfavorably to Marvel and criticized the character of Steppenwolf.

The website's consensus reads: "Justice League leaps over a number of DC movies, but its single bound isn't enough to shed the murky aesthetic, thin characters, and chaotic action that continue to dog the franchise.

[145] Richard Roeper of the Chicago Sun-Times gave the film 3.5 out of 4 stars, praising the cast, especially Gadot, and saying "It's a putting-the-band-together origins movie, executed with great fun and energy.

"[164] Conversely, Todd McCarthy of The Hollywood Reporter, while praising Gadot and Miller, called the film visually ugly and boring, saying, "Fatigue, repetition and a laborious approach to exposition are the keynotes of this affair, which is also notable for how Ben Affleck, donning the bat suit for the second time, looks like he'd rather be almost anywhere else but here.

"[155] Writing for The Washington Post, Alyssa Rosenberg also returned with a negative review, and described the film was a "symbol of just how entrenched superhero movies have become in the Hollywood ecosystem, it's also a potent illustration that success hasn't necessarily artistically elevated the genre."

[190] By March 2017, producer Charles Roven said that Zack Snyder would direct the film[191] and in October J. K. Simmons stated that the studio was working on the script of the sequel, alongside The Batman.

[193] In December, it was revealed that there were "no immediate plans" for Zack Snyder to direct any future DC films, being relegated to an executive producer position instead.