Since 2006, DC Comics have produced regular animated films based on their iconic characters; usually, the films adapt particular comic storylines. Up until 2013, these films were mostly standalone projects, but that changed in 2013 with The Flashpoint Paradox. From Justice League: War to Justice League Dark: Apokolips War, the animated DC films operated as a shared universe.
This new universe took much inspiration from DC's New 52 comics reboot, adapting the aesthetics and storylines. By the end, though, the movies started to adapt older storylines as well, such as The Death Of Superman, Batman: Hush, and Teen Titans: The Judas Contract. That wasn't the only thing that changed—several voice actors were recast between films as well.
10 Recast: Jerry O'Connell Took Over Superman From Alan Tudyk
In Justice League: War, Superman was voiced by Alan Tudyk. From Justice League: Throne Of Atlantis onward, the Man Of Steel was instead played by Jerry O'Connell (in a sweet bit of casting, O'Connell's wife Rebecca Romijn started voicing Lois Lane). Superman also went from a hot-blooded bully in War to the more traditional Big Blue Boy Scout.
Tudyk was an odd choice, to begin with; a character actor who specializes in either comedy or villains isn't who one usually thinks of when it comes to Superman. Tudyk might have been better served as Clark Kent, but Superman's human identity was never shown in War.
9 The Same: Jason O'Mara Played Batman 11 Times
The most consistent voice actor across all the films was Jason O'Mara as Batman. Batman appeared in all the Justice League (Dark) films, his own solo series, and The Death Of Superman/Reign Of The Supermen. Indeed, the only films in which the Caped Crusader didn't show up were The Judas Contract, Suicide Squad: Hell To Pay, Constantine: City Of Demons, and Wonder Woman: Bloodlines.
O'Mara's consistent run as Batman makes him the prolific runner-up to the most famous Batman voice actor, Kevin Conroy (Conroy voiced Bruce in The Flashpoint Paradox and then his father, Thomas Wayne, in Batman vs Robin).
8 Recast: First Michelle Monaghan Played Wonder Woman, Then Rosario Dawson
Batman was the only member of the Trinity to make it through the New 52 animated universe without a recast. Wonder Woman debuted alongside the rest of the JL in War, voiced by Michelle Monaghan. The character was played mostly for comedy, whether through her brashness or her being a fish out of water in a "man's world" (e.g. her reaction to trying ice cream for the first time).
In Throne Of Atlantis, Rosario Dawson stepped into the role and kept it until the end, including in Diana's solo prequel Wonder Woman: Bloodlines. Dawson's deeper, calmer voice was a better fit for the classic Diana than Monaghan would've been.
7 The Same: Shemar Moore Stayed On As Cyborg
Justice League: War was a direct adaptation of Geoff Johns' and Jim Lee's first volume of Justice League—that was the comic that kicked off the New 52, so it was only fitting that it kick off the post-Flashpoint Paradox animated DC movies. One of the major changes Johns and Lee made to the JL was swapping out Martian Manhunter as a founding member for Cyborg.
The hero's origin was likewise rewritten to be the result of Victor Stone merging with a Mother Box. Cyborg had one of the more consistent arcs across the movies, accepting his transformation and ultimately sacrificing himself to destroy Apokolips. It's fitting that he had the same actor throughout, Shemar Moore.
6 Recast: Green Lantern Went From Justin Kirk To Nathan Fillion
Like Wonder Woman, Green Lantern was played for comedy at his own expense in Justice League: War. While the favorite of the source material's writer, Hal spends most of War being shown up, whether by Batman, Superman, or Darkseid. In that film, he was played by Justin Kirk (currently sleazing it up as neo-fascist presidential candidate Jeryd Mencken on Succession), and his voice definitely made Hal as punchable as his behavior did.
Later movies toned down Hal's brashness, and recast. Like Superman and Wonder Woman, Hal had a new actor from Throne Of Atlantis onward. Specifically, Nathan Fillion, who previously voiced Hal in Green Lantern: Emerald Knights.
5 The Same: Christopher Gorham Was Always The Flash
The Flash is the lynch point of the New 52. In both film and comics, Barry Allen traveling back in time to stop his mother from being murdered is the event that kicks off the universal reset. In the finale movie, Justice League Dark: Apokolips War, Barry is forced to repeat the Flashpoint to undo the irreparable damage Darkseid did to the world.
From Justice League: War to Apokolips War, the Flash was voiced by Christopher Gorham, putting him in the half of the Justice League who didn't get recast.
4 Recast: Lex Luthor Was Handed Off From Steve Blum To Rainn Wilson
Lex Luthor may be Superman's greatest enemy, but it took him a while to receive focus in the New 52 animated movies. He first appeared in the post-credits scene of Justice League: Throne Of Atlantis, offering Ocean Master membership in the Legion of Doom—this is followed up with a brief fight between the League and Legion in Justice League vs Teen Titans.
However, Death Of Superman/Reign Of The Superman/Apokolips War finally bring Luthor into the spotlight, adapting his membership in the Justice League from the latter part of Johns' JL run. In his earliest appearances, Luthor was voiced by Steve Blum, but for his final three, Rainn Wilson took over.
3 The Same: Sean Maher Played Nightwing In All His Appearances
The four Batman solo films in the New 52 universe focus heavily on building up the Bat-Family. By the time of Son of Batman, Dick Grayson has already become Nightwing. Dick appears throughout the Batman and the Teen Titans films. In Batman: Bad Blood, he even got to put on the cowl after Bruce was abducted.
In all the movies, Dick is voiced by Sean Maher, who's a perfect fit for the part. He's got the confidence, but he's nowhere near as hardened as Batman, a contrast especially obvious in Bad Blood.
2 Recast: Steve Blum Also Lost Darkseid To Tony Todd
Luthor wasn't the only villainous part that Steve Blum lost out on. In Justice League: War, he voiced the God of Evil himself, Darkseid. However, Blum's normal voice is too suave to pull off the booming baritone of Darkseid, and as a result, it was modulated so low that Blum's natural voice was buried too deep to make out.
When Darkseid returned in Reign Of The Superman and Apokolips War, he was instead voiced by Tony Todd, whose naturally deep voice was a better fit for the character.
1 The Same: Damian Wayne Saw Consistent Growth Voiced By Stuart Allen
Damian Wayne was one of the starring characters of the New 52 films. Son Of Batman was one of Damian's first appearances outside of comics, and the Batman films took much inspiration from Grant Morrison's Batman run where Damian debuted. Over the course of the films, Damian goes from a violent brat to a hero, and becomes much closer to his father along the way.
Tracking with this character development, he also has the consistent voice work of Stuart Allen across all his appearances, from Batman and Teen Titans to finally Apokolips War.