Trivia about The Flash.
- After the success of Batman in 1989 Jon Peters and Peter Guber in 1991 were going to produce the film, Jeph Loeb wrote the script and Michael J. Fox, Tom Cruise, Kevin Bacon, Eric Stoltz, and Emilio Estevez were all considered for the role of Wally West or Barry Allen, but the film was cancelled.
- In 2004, Warner Bros. announced that David S. Goyer would direct, write and produce a Flash film, with Ryan Reynolds considered to play Barry Allen. The project dissolved in 2007, when Goyer left over creative differences.
- Bradley Cooper, Chris Pine, Ryan Kwanten, Matthew Fox and Scott Porter were all linked with the role of Barry Allen.
- The movie will focus on Barry Allen, the second Flash.
- Director Shawn Levy was originally attacted to direct the movie after David S. Goyer left but then he dropped out and then David Dobkin took over as the director for a while and then he also dropped out as well.
- When David S. Goyer was attached to the movie the number one choice and the actor most interested in playing the role of The Flash was actor Ian Somerhalder and The Flash he would be portraying would be the 3rd Flash Wally West.
- Ezra Miller was announced to play the iconic hero of Flash on October 15, 2014, making him the youngest actor to ever play a DC comic role.
- Ezra Miller is the second openly LGBT person to play a character in the DC Extended Universe. Cara Delevingne is the first, portraying June Moone / Enchantress in Suicide Squad.
- When it was announced that Ezra Miller would be playing The Flash a lot of fans disliked the decision: those defending him voiced their support with the hashtag #supportezramiller.
- The film is confirmed NOT to be an origin story.
- It will star a different lead for Barry Allen, confirming no connection between the TV universe and movie universe.
- Zack Snyder and Producer Greg Berlanti were linked with Directing.
- Flash was originally in the hands of Phil Lord and Christopher Miller who went on to direct Solo: A Star Wars Story. The mantle was then passed to Seth Grahame-Smith to direct the movie who is also the screen writer. He later on left the project due to creative differences. "'Dope director Rick Famuyiwa was brought in to take care of the mantle who also left the project due to creative differences. Lord and Miller who were later fired from directing the Han Solo film were now in talks to direct. John Francis Daley and Jonathan Goldstein were hired to co-direct but later dropped out over creative differences.
- James Wan was considered by Warner Bros. to direct a film about either Aquaman or The Flash. He ultimately chose to do Aquaman (2018) as he saw it as an opportunity to do something original and unique in the superhero genre.
- Robert Zemeckis, Sam Raimi, Matthew Vaughn and Marc Webb were the frontrunners for to direct the film, however, Raimi and Webb passed on the project. Christopher Miller and Phil Lord are also under consideration to direct.
- John Francis Daley and Jonathan Goldstein who wrote drafts of the script and were slated to helm the project, have moved on.
- This movie is going to have an even lighter tone compared to Justice League.
- The third adaptation based on the Flashpoint storyline after Justice League: The Flashpoint Paradox and season 3 of "The Flash".
- At San Diego Comic Con 2017, it was announced that this film would be an adaptation of The Flashpoint Paradox storyline. This means Jeffrey Dean Morgan could be reprising his role as Thomas Wayne from Batman v Superman: Dawn of Justice.
- Julia Roberts, Julianne Moore, Vera Farmiga, Kate Winslet and Hilary Swank were considered for the role of Nora Allen.
- Rita Ora, Lucy Boynton, Kathryn Prescott and Stefanie Scott were the frontrunners for Iris West before it went to Kiersey Clemons.
- Kiersey Clemons was originally going to be introduced as Iris West in Justice League. However, her scenes were cut in the final film.
- Ezra Miller and Billy Crudup previously starred together in the "Stanford Prison Experiment".
- Has no connection to the TV-series "The Flash".
- This will be the second movie in the DC Extended Universe to be filmed entirely with IMAX cameras by Henry Braham, BSC, after The Suicide Squad (2021).
- This will be Christina Hodson's second DC Extended Universe film that she has worked on after Birds of Prey (2020).
- This film will reportedly feature Ben Affleck as the Batman for the final time in the DCEU.
- The film was initially scheduled for release on March 23, 2018, when Warner Bros. first announced their slate of DCEU films, before it was moved to March 16 of the same year. In July 2016, this release date was assumed by Warner Bros. Pictures' Tomb Raider and The Flash was not given another release date at that time. When Andy Muschietti was hired as director in July 2019, the film was slated for release on July 1, 2022, it was then moved up to June 3, 2022, the film was moved to November 4, 2022, when Warner Bros. shifted its release schedule due to the COVID-19 pandemic. In March 2022, it was moved to the June 23, 2023 release date to its current March 2023 date for additional post production work on CGI special effects that were needed as a result of the impact of the coronavirus pandemic on the film industry.
- Billy Crudup was set to reprise his role as Henry Allen but later dropped out due to scheduling conflicts.
- Producer Barbara Muschietti's liking on a post on Instagram, comparing Sasha Calle to the Cir-El version of Supergirl, ignited fan theories that Calle is actually going to portray this character in the film. Calle later shared a picture of herself sporting a shorter hairstyle, also compared to Cir-El's. The first look on her in costume during filming in London suggested this Supergirl is based on Lara Lane Kent, from the "Injustice" universe.
- Not only does this film mark Michael Keaton's reprisal as Batman in 31 years, but it's the first ever Flash movie too. Up to this point, projects of The Flash have only ever been part of television.
- Rumored to have Jeffrey Dean Morgan and Lauren Cohan as the Flashpoint versions of their 'Batman V Superman' characters Thomas and Martha Wayne. In the alternate timeline it was Bruce who was killed outside the theatre not his parents. This resulted in Martha suffering an emotional breakdown and becoming The Joker and Thomas becoming The Batman to stop her.
- This film is based on the "Flashpoint" storyline, where the Flash travels into an alternate universe where the world is in chaos and he must locate and bring together a Justice League to make things right.
- Concept art for the Flash suit is similar to the first suit in "The Flash". It's shown to be a dark red armor like suit with a giant lightning bolt in the center of the chest without any circle around it or lightning bolts on the mask.
- Rob Lowe was approached to play one of the villains in the film.
- James Norton, Billy Magnussen, Charlie Hunnam, Alexander Skarsgard and Michael Fassbender were all in the running for Reverse Flash and Jessica Chastain was up for a gender-swapped version of Reverse Flash.
- There are rumors that Andy Muschietti wants to do a female version of Mirror Master with actresses such as Sylvia Hoeks, Claire Foy and Mackenzie Davis mentioned as choices.
- Christian Bale would have reprise his role as Bruce Wayne/Batman from The Dark Knight trilogy if the deal with Michael Keaton dosen't work.
- Taylor Russell, Alexandra Shipp and Laura Harrier were rumored to replace Kiersey Clemons as Iris West.
- Sasha Calle is the first Latina to play Supergirl.
- Brazilian actresses Bruna Marquezine and Isis Valverde auditioned for the role of Supergirl before Sasha Calle was cast.
- Sasha Calle did a chemistry test with Ezra Miller as part of her audition, which also included Mexican and Brazilian actresses, such as Bruna Marquezine and Isis Valverde. The two actresses were top choices for the role, but the COVID-19 pandemic prevented them from traveling to London.
- Anna Camp and Natalie Dormer are rumored casting choices to play as Captain Cold's sister Lisa Snart aka Golden Glider.
- Claire Foy, Sylvia Hoeks, Mackenzie Davis, and Lizzy Caplan were rumored to play a female Mirror Master.
- Fans all wanted Lucas Till to replace Ezra Miller as Barry Allen/THe Flash when the actor was working on a new script with Grant Morrison.
- This film reunites screenwriters Jonathan Goldstein and John Francis Daley and actor Michael Keaton from the MCU film Spider-Man: Homecoming. Keaton played Adrian Toomes/Vulture in that film.
- Grant Gustin denied the report that his Barry Allen/The Flash the TV series The Flash will be appearing in the movie.
- Warner Bros released both the trailer and TV spot on February 12, 2023 during Super Bowl LVII, 3 character posters of The Flash, Batman and Supergirl on February 13, 2023 and the first photo of Michael Keaton as Bruce Wayne on February 14, 2023.