After X-Men: Days of Future Past (2014) erased the events of X-Men: The Last Stand (2006) from the series' timeline, Kinberg expressed interest in a new adaptation of Chris Claremont and John Byrne's "The Dark Phoenix Saga" in a future film that would be more faithful than his previous attempt with The Last Stand, which was met with a mixed reception, with even Kinberg and co-writer Zak Penn ultimately unimpressed with the film.

Filming began later that month in Montreal and was completed in October 2017; the entire third act was reshot in late 2018 after test screenings yielded poor responses.

Xavier reveals to the other X-Men that he suppressed Jean's memory of causing the car crash as a child to keep the psychological trauma from making her unstable, but her enhanced power is destroying the mental blocks and she is now experiencing PTSD symptoms.

Hank McCoy, blaming Xavier for Raven's death, leaves the school and allies with Lehnsherr and his faction of mutants in a plan to kill Jean in New York City.

While sitting at a café on Rue de la Paix, Paris, Xavier is surprised by Lehnsherr, who invites him to a game of chess, while a flaming phoenix appears high in the sky.

Other cast members include Scott Shepherd as John Grey, Jean's father; Ato Essandoh as Jones, Vuk's second in command; and Brian d'Arcy James as the President of the United States.

Veteran X-Men writer Chris Claremont makes a cameo appearance as a White House guest during the scene in which Xavier accepts his award for rescuing the crew of the space shuttle Endeavour.

He added that he also hoped to see the cast of the previous trilogy of films return, namely James McAvoy as Charles Xavier, Michael Fassbender as Erik Lehnsherr / Magneto, and Jennifer Lawrence as Raven Darkhölme / Mystique.

McAvoy, Fassbender, Lawrence, and Nicholas Hoult's contracts from the previous trilogy had ended, but Kinberg was optimistically writing the new script with them in mind.

The new members were Harry Leland, Friedrich von Roehm, Fenris, Shinobi Shaw, and the Red Lotus gang (whom Andrew Stehlin was set to play).

[43] In pitching the film to the studio, Kinberg used real world imagery, such as footage of disasters and lightning strikes, and focused on an organic and grounded approach as a response to criticisms of Apocalypse's heightened reality.

In addition to Turner, Apocalypse actors Alexandra Shipp, Tye Sheridan, and Kodi Smit-McPhee were also confirmed to be returning, while producers for the film were revealed to be Kinberg and Parker.

[64] He later clarified that the film would still include alien characters as in the comic storyline, an element that was ignored for the Last Stand adaptation, but which he felt was integral to the story.

[69] He also explained that he "felt in his gut" that this was the story he needed to tell once Singer left the franchise, and that his vision for the film was "so clear in my head, emotionally and visually, that it would have killed me to hand this to somebody else to direct."

[70] Lawrence revealed that she had worked to convince Kinberg to direct the film, and had promised to return for it if he did so, despite her dislike of the make-up required to portray her character.

[72] This was because Fox and Kinberg wanted to schedule some routine reshoots for the film after receiving feedback from audiences during a test screening, but were not able to get all of the necessary cast members together until August or September 2018.

[74] Addressing the reshoots, Kinberg confirmed the scheduling delays, and described the photography as a "normal" part of the film's creation that would allow him "enough time to have it ready and looking perfect.

[79][80] The move was also reportedly to appease James Cameron, who had Alita: Battle Angel (2019) moved from December to February due to concerns Cameron had about releasing Alita during a crowded holiday season and did not want competition from another Fox would-be blockbuster; Kinberg and Dark Phoenix producers opposed the change, as the film was not made for a summer release and was facing heavy competition.

[84] Hans Zimmer was reported to compose music for the film in January 2018,[85] despite his statement in March 2016, saying that he had officially retired from the "superhero business",[86] following his experience working on Batman v Superman: Dawn of Justice (2016).

[87] In another interview that September, Zimmer justified his statement on his conversations with Ron Howard, who convinced him not keep to a "blanket" view and avoid an entire genre, instead focusing on waiting for the right story.

[92] Fox Music and Zimmer's studio company Remote Control Productions released the album on August 5, 2019, which received a fairly positive response.

[94] Graeme McMillan and Aaron Couch of The Hollywood Reporter wrote that this feeling could have been avoided if the trailer had shown more of the film's space and alien elements, which would have differentiated it from the Last Stand adaptation.

[99] Deadline Hollywood reported that they had been hearing about the marketing campaign being in disarray since February and cited this as a major factor in the film's financial failure.

[108][97] In the United States and Canada, Dark Phoenix was released alongside The Secret Life of Pets 2, and was initially projected to gross $50–60 million from 3,721 theaters in its opening weekend, with the studio expecting a $50-million debut.

The site's critical consensus reads: "Dark Phoenix ends an era of the X-Men franchise by taking a second stab at adapting a classic comics arc—with deeply disappointing results.

"[120] Matt Goldberg of Collider gave the film a grade of "D" and wrote, "When Marvel Studios inevitably reboots X-Men, a movie like Dark Phoenix will be a forgotten relic.

Other than that, though..."[122] Rodrigo Perez of The Playlist said: "Its atrocious, expository dialogue, cumbersome plot, whiplashing character motivations, unintentionally funny moments, and often corny costumes ensure Dark Phoenix will be remembered in the annals of mediocre movies.

"[123] Conversely, Variety's Owen Gleiberman summarized his positive review with, "The X-Men franchise wraps up... with a functionally plotted sequel that attains a note of ominous majesty, thanks to Sophie Turner's presence as an X-Woman consumed by the awesomeness of her power.

[140] Claremont remarked, "My problem with both iterations of Dark Phoenix onscreen, the original by Brett Ratner and the newer version by Simon Kinberg, is, I don't think you can do it effectively in 90 minutes.

[152] Additionally, Karan Soni, Leslie Uggams, Morena Baccarin, Stefan Kapičić, Rob Delaney, Brianna Hildebrand, Lewis Tan and Shioli Kutsuna reprised their roles as Dopinder and Blind Al, Vanessa Carlysle, Colossus, Peter Wisdom, Negasonic Teenage Warhead, Shatterstar and Yukio from the previous Deadpool films, respectively.