The film features an ensemble cast of Adam Driver, Giancarlo Esposito, Nathalie Emmanuel, Aubrey Plaza, Shia LaBeouf, Jon Voight, Laurence Fishburne, Talia Shire, Jason Schwartzman, Kathryn Hunter, Grace VanderWaal, Chloe Fineman, James Remar, D. B. Sweeney, and Dustin Hoffman.

It endured a troubled run-up to release: a trailer was removed for using fabricated pull quotes, and Coppola sued trade publication Variety for libel after it published allegations of sexual misconduct by him on set.

Growing up in New York City, Francis Ford Coppola was fascinated by science fiction films, such as Fritz Lang's Metropolis (1927) and William Cameron Menzies's Things to Come (1936), and the scientific community's history with dangerous experiments.

[6] His reading of the Roman historian Sallust and William Bolitho Ryall's book Twelve Against the Gods (1929) inspired him to make a film about Lucius Sergius Catiline, a populist who promised to forgive debts if elected to the consulship.

[6][19] In mid-1983, he described the plot as taking place in one day in New York City with Catiline Rome as a backdrop, similar to how James Joyce's Ulysses (1922) used Homer in the context of modern Dublin and how he updated the setting of Joseph Conrad's Heart of Darkness (1899) from the late 1800s amid European colonial rule in Africa to the 1970s Vietnam War for Apocalypse Now.

[6][20]: 74 [21]: 215 In January 1989, Coppola announced his plans to move to Italy to work on two productions in the next five years, including Le Ribellion di Catilina, a film "so big and complicated it would seem impossible", which biographer Michael Schumacher said "sounded much like what he had in store for Megalopolis".

[18]: 436  However, the film was postponed to "no earlier than 1996" after Coppola found himself prioritizing other projects, including Bram Stoker's Dracula (1992), Jack (1996), and The Rainmaker (1997), to get out of debt accumulated from the box-office failures of One from the Heart (1982) and Tucker: The Man and His Dream (1988).

[19] In 2001, he held table reads in a production office in Park Slope, Brooklyn, with actors including Nicolas Cage (his nephew), Russell Crowe, Robert De Niro, Leonardo DiCaprio, Giancarlo Esposito, Edie Falco, James Gandolfini, Jon Hamm, Paul Newman, Al Pacino, Parker Posey, Kevin Spacey, and Uma Thurman.

[19][22]: 263  After the September 11 attacks, during which Coppola and his team were location scouting in New York, the roughly thirty hours of footage was stashed, including more material they shot two weeks after, due to its resemblance to the script, which involved a Soviet satellite crashing into Earth and destroying a section of Lower Manhattan.

[1]: 3 [52] In August 2022, Kathryn Hunter, Aubrey Plaza, James Remar, Jason Schwartzman (Coppola's nephew), and Grace VanderWaal joined the cast, with LaBeouf and Shire confirmed as part of it.

Before the meeting, Coppola emailed her the entire script and asked her to consider the role of "Wow Platinum", wanting an actress with a similar screen presence to Jean Harlow and Myrna Loy in screwball comedies from the 1930s.

[61][62] Recognizing Driver from her New York University days and feeling Megalopolis was a reminder to every actor's dreams to do theatre, Fineman looked for William Shakespeare's "trustafarians characters as an inspiration and improvised like she had done in past projects such as Damien Chazelle's Babylon and Noah Baumbach's White Noise (both 2022).

[41] The film's literary influences included the books Bullshit Jobs (2018), The Dawn of Everything (2021), and Debt: The First 5000 Years (2011) by David Graeber; The Chalice and the Blade (1987) by Riane Eisler; Directors on Directing (1963), edited by Toby Cole and Helen Krich Chinoy, particularly an entry by Elia Kazan on his approach to A Streetcar Named Desire (1951); Dream of the Red Chamber by Cao Xueqin; Elective Affinities (1809) by Johann Wolfgang von Goethe; The Glass Bead Game (1943) by Hermann Hesse; The Origins of Political Order (2011) by Francis Fukuyama; The Swerve (2011) by Stephen Greenblatt; To the Lighthouse (1927) by Virginia Woolf; Twelve Against the Gods (1929) by William Bolitho Ryall; and The War Lovers (2010) by Evan Thomas.

[63] Plaza described the workshop-style approach as allowing actors to improvise and provide feedback to the script, adding: "We wrote scenes and we conducted ourselves like a theater troupe, me and Jon Voight and Shia [LaBeouf].

[58] Others described that approach as "exasperating" and "old-school", as Coppola was hesitant to decide how the film would look and would spend work days completing shots practically instead of relying on digital techniques.

In response, executive producer Darren Demetre said, "Francis walked around the set to establish the spirit of the scene by giving kind hugs and kisses on the cheek to the cast and background players.

[85] Videos of the encounters at the Tabernacle surfaced in July 2024; sources told Variety that Coppola often inadvertently inserted himself into frame while interacting with extras and announced on a microphone after multiple takes, "Sorry, if I come up to you and kiss you.

[89][90] She alleged that during the filming of the club scene on February 14, Coppola kissed her cheek, touched multiple parts of her body without her consent, including her back and waist, made sexual comments about her appearance, and encouraged her to "sit on his lap and call him 'uncle'".

After Variety published further articles regarding his alleged misconduct, he filed a libel lawsuit against them and journalists Brent Lang and Tatiana Siegel on September 10, seeking $15 million and further punitive and exemplary damages.

[7] The Sweet East (2023) screenwriter Nick Pinkerton expressed concern that Pulcher's rapid recruitment of working-class populists implied that "the plebeians [are] easily manipulated rubes, a curious omission in a movie that's positioned as a humanist hymn to our species' higher potential".

[133] Ryall had direct input and liberty from Coppola, while Phillips said he was "drawing this book (on and off) since December 2022" and wrapped his part of the 148-page comic adaptation in July 2024; the screenplay and concept art served as foundations for the novel.

On August 21, Lionsgate released a trailer that opened with snippets of negative reviews for Coppola's The Godfather, Apocalypse Now, and Bram Stoker's Dracula followed by 90 seconds of footage from Megalopolis, all accompanied by Fishburne's narration that "True genius is often misunderstood" and "One filmmaker has always been ahead of his time" before naming the film "an event nothing can prepare you for".

The unconventional tactic, according to Rolling Stone's Daniel Kreps, attempted to combat the film's mixed reception at Cannes by pointing out "similarly misguided critical assessments of Coppola's previous masterpieces".

[145] However, Vulture's Bilge Ebiri verified that the blurbs cited in the trailer were fabricated, including those credited to Vincent Canby, Roger Ebert, Owen Gleiberman, Pauline Kael, Stanley Kauffmann, Rex Reed, Andrew Sarris, and John Simon.

The publication also seemingly confirmed the use of an AI engine to generate the quotes and wondered why Egan was the only person blamed, writing, "The trailer was almost certainly vetted by a half-dozen others, including top brass at the studio and its marketing team, none of whom spotted the error, and they are keeping their jobs".

[154] Kaitlyn Booth of Bleeding Cool criticized the video's ambiguity in describing the plot, writing: "It seems that Lionsgate and whoever is behind this marketing has decided the best way to go about pitching a very complex film to the public is not to try and hope that the prestige from director Francis Ford Coppola will be enough".

[155] Created by the duo Awkward Moments, the music for the ad features an 852 Hz frequency, which they claim "stimulates the third eye chakra...  a powerful tool for those seeking to expand their spiritual awareness and tap into higher levels of consciousness".

They mentioned that the film's "blockbuster cast" and IMAX release was "no guarantee of audience interest", given Driver's box-office disappointment in "high-concept sci-fi" with 65 the year prior and that the last Coppola–helmed movie to open above $5 million was Supernova (uncredited) in 2000.

[119] Marc Tracy of The New York Times likened the film to Joseph L. Mankiewicz's notorious box-office flop Cleopatra (1963) and other "ambitious, big-budget spectacle that got out of hand during production and crashed upon contact with the viewing public".

[187] Nicholas Barber of the BBC panned the movie, criticizing its "incoherent plot", "stilted dialogue", narrow use of "big-name actors" like Hoffman and Schwartzman, the contrast between "Driver taking it all so seriously, while Plaza goes gloriously over the top ... [and] LaBeouf prances around chewing the scenery to shreds", and the "horribly cheap and amateurish" visual effects.