No Colin Farrell, Michael Fassbender or (well, he was rumoured to be in the film for a while there) Pierce Brosnan here.
Deadpool 2 has, according to Deadline, set a major villain, and the actor to play him.
The baddie in question will be Black Tom who is “a nemesis in the X-Men universe, a Dublin-born mutant who can manipulate, bond with, and project energy through plant life.” Well he’s Irish, so there has to be some connection to nature/greenery in there. The character is also “capable of issuing concussive blasts with a wooden object, usually a shillelagh.”
Deadline reports that 20th Century Fox have cast Jack Kesy in the role. Kesy has had roles in TV series like Ray Donovan and The Strain, and has a bunch of more movies coming out. He plays Leon in the upcoming Baywatch so that should be a big one to familiarise him with audiences.
Deadpool 2 is directed by David Leitch and is set for release in June 2018. Ryan Reynolds returns as the Merc with a Mouth while also returning to the cast are Morena Baccarin as Deadpool’s love interest Vanessa, Leslie Uggams as Blind Al, Stefan Kapacic as the big guy Colossus, and Brianna Hildebrand as Negasonic Teenage Warhead.
Josh Brolin has already been set to play the principal villain, Cable, and Zazie Beetz has been cast as Domino.