Fans have been waiting quite a while for The Flash solo film to develop in the DC Extended Universe since Ezra Miller's first appearance as Barry Allen back in 2016's Batman v Superman: Dawn of Justice since a few director changes and issues behind-the-scenes kept delaying the project, but the movie is finally moving forward.
Given the lengthy nature of the film's development, there have been a number of rumors that have popped up over the last couple of years that tie into the rumored Flashpoint comic adaptation and teased a few characters that may or may not be appearing, so it's worth exploring a few of the rumored and confirmed characters who will show up in The Flash.
10 CONFIRMED: Ron Livingston Will Replace Billy Crudup As Henry Allen
Billy Crudup debuted as Barry's father Henry Allen in Justice League with a slightly enhanced role in HBO Max's 2021 release of Zack Snyder's Justice League, though due to the lengthy in-development phase of The Flash, scheduling issues have forced him to drop out of the role.
Ron Livingston was available and later cast in the role of Henry Allen in the solo film, which will likely further explore his wrongful imprisonment after the murder of his wife and Barry's attempts to prove his innocence.
9 RUMORED: Ray Fisher Could Still Return As Cyborg As Originally Planned
Early reports for The Flash revealed that the story was originally conceived as a buddy superhero movie that also starred Ray Fisher's Victor Stone/Cyborg from Justice League after the two characters bonded during the team's formation.
Unfortunately, Fisher's poor treatment during Whedon's takeover of the film and his unhappiness with Cyborg's reduced role led to a public fallout and call for accountability with Warner Bros. executives. This led to his character being written out of The Flash, though Fisher says he is willing to return given that proper actions are taken on WB's end.
8 CONFIRMED: Kiersey Clemons Will Be Reprising Her Role As Iris West
While Kiersey Clemons' debut in the role of Iris West was initially cut from the theatrical release of Justice League, the scene was brought back for Zack Snyder's Justice League to tease her eventual full debut in The Flash, though there was concern the role would also have to be recast.
Thankfully, Clemons has been confirmed to reprise the role of Barry Allen's love interest Iris West, though it's unclear whether their first meeting in the "Snyder Cut" will be referenced given the non-canon nature of the "SnyderVerse."
7 RUMORED: Reverse-Flash Has Been Rumored As The Main Villain
There have been a few details about the story and characters that will appear in The Flash movie, though fans have yet to receive confirmation about the main villain of the movie beyond rumors that Reverse-Flash will appear in the movie.
Eobard Thawne's presence in The Flash is no surprise if the movie does adapt the Flashpoint storyline as rumored given the character's role both in the event and the death of Barry Allen's mother. However, there have also been rumors that Reverse-Flash was cut from the movie in order to build his threat for sequels, so this remains unconfirmed.
6 CONFIRMED: Maribel Verdú Joined The Cast As Nora Allen
While Barry Allen's mother Nora was briefly mentioned in both versions of Justice League, the character was only recently confirmed to appear in The Flash after rumors that her death would play a large role in the potentially Flashpoint-based adaptation.
Maribel Verdú (Pan's Labyrinth, Y Tu Mamá También) signed on to play Nora Allen in The Flash, which could take place both in the past and in an alternate present where she is alive if Flashpoint is followed for the movie.
5 CONFIRMED: Ben Affleck Will Be Returning As The DCEU's Batman
While fans thought Ben Affleck was done with the role of Bruce Wayne/Batman given Robert Pattinson's upcoming debut in The Batman, the DCEU's version of the Dark Knight will continue on in The Flash following Affleck's confirmed return.
Given Barry and Bruce's established relationship in Justice League, Ben Affleck's return makes a lot of sense and also lends strength to the rumors that Barry Allen's new high-tech suit in The Flash that was teased in concept art is possible because of Wayne's resources.
4 CONFIRMED: Michael Keaton Will Be Appearing As A Multiversal Batman
Ben Affleck isn't the only Batman that will be appearing in The Flash, as Michael Keaton's popular version of the character from Tim Burton's 1989 hit Batman was first teased in concept art that also revealed a glimpse at Barry's new suit.
After rumors and contradictory statements from Keaton himself, the actor's return to the role of Batman after almost 25 years was recently confirmed, which also confirms that The Flash will explore DC's multiverse that first saw the character interact with his TV counterpart in The CW's Crisis on Infinite Earths crossover specials.
3 RUMORED: Wonder Woman & Aquaman Are Rumored To Appear As Their Flashpoint Versions
The Flashpoint event in the comics saw Barry Allen dramatically alter the timeline and create an alternate reality where he had never gained super-speed to become The Flash, which was only the beginning of a number of changes to the DC Universe.
The Flashpoint timeline was on the brink of destruction as the Atlanteans and the Amazons waged war against each other that was set to consume the planet. While Gal Gadot and Jason Momoa haven't been confirmed to reprise their respective roles of Wonder Woman and Aquaman for The Flash, rumors of their appearance in Flashpoint versions have persisted.
2 CONFIRMED: Sasha Calle Has Been Confirmed As The DCEU's Supergirl
One of the biggest announcements to come from the renewed development of The Flash after director Andy Muschietti signed on for the film was the addition of Sasha Calle (The Young And The Restless) as the DCEU's Supergirl.
The existence of Supergirl in the DCEU has been rumored for years since Man of Steel teased the presence of other Kryptonians on Earth, so Calle's casting as Supergirl could be tied to that previous mystery or potentially be a multiversal or altered timeline take on the character.
1 RUMORED: Jeffrey Dean Morgan & Lauren Cohan Are Rumored To Return As Flashpoint's Batman & Joker
Batman v Superman: Dawn of Justice retread the repeatedly established death scene of Thomas and Martha Wayne that led to Bruce Wayne's costumed life as the Dark Knight, though Jeffrey Dean Morgan and Lauren Cohan were cast to play the small but powerful roles.
This led to speculation that the actors were being set up for future roles as those characters in a Flashpoint adaptation, which saw Bruce Wayne murdered in the alternate timeline, leading Thomas and Martha Wayne to become Flashpoint's Batman and The Joker. Unfortunately, their appearance in The Flash has yet to be confirmed despite the fan demand for the characters.