Brett Ratner directed X-Men: The Last Stand, Matthew Vaughn directed X-Men: First Class and Simon Kinberg, who’s been attached to the franchise since The Last Stand, is making his directorial debut with Dark Phoenix.
As far as the main X-Men film series is concerned, half of it has been directed by the same man: Bryan Singer, who kicked off the franchise in 2000 and ended his run with X-Men: Apocalypse in 2016.