Both heroes will be officially introduced next year when they join forces with Batman, Superman, Wonder Woman and Aquaman in Justice League.
Batman v Superman: Dawn of Justice introduced set up how many superheroes are living in the DC Extended Universe, but next year, Justice League will see many of these heroes officially teaming up.
Both heroes were introduced via cameos in Batman v Superman: Dawn of Justice, and Flash briefly appeared earlier this year in Suicide Squad.
News just broke that he’ll be joined by his fellow Justice League teammate, Cyborg.