The Clown prince of Evil is the unknown Arkham convict in the cell next to The Riddler, but here's who plays joker in The Batman. When Edward Nashton aka The Riddler is vanquished and strikes out inside Arkham State Hospital near the end of the movie, the individual in his next cell stands up and indirectly identifies himself as the Joker.
The joker is not just the most famous Batman adversary, but also one of the most famous mobsters of all time. Thus far, every live-action Batman has fought his own joker, occasionally openly and sometimes indirectly. From Caesar Romeero to Jack Nicholsson, the joker was the go-to adversary to have go up against Batman in the initial periods, before graphic novel movies and tv series became the standard.
Bary Keogghan, who portrays the joker in The Batman, is up next. In one of the film's last moments, the joker presents Riddler with his own riddle, the solution to which is friend, foreshadowing the development of Batman's rogues gallery in this new trilogy. Despite the fact that he only featured momentarily in the film and was mostly hidden behind a window, it's expected that Keoghan will reprise his role as the joker in The Batman 2, giving him the chance to deliver his own take on the legendary hero.