The troubled star, who has battled a series of legal battles and a child custody case since he last portrayed John Connor in a "Terminator" movie, will be back as the son of Hamilton's freedom fighter, Sarah Connor, in new movie "Terminator: Dark Fate".
The casting news was made official at San Diego Comic-Con on Thursday (July 18), where Schwarzenegger and Hamilton appeared to promote the latest sequel and chat about their iconic characters.
Arnold told fans he will never tire of playing a robot in the films. "Of course I need to come back," he shared. "I'm addicted to Terminator. Terminator was the movie that really launched my action movie career... From that moment on, everything has changed in my life."
"It was one of those really unique characters where you were amongst the top 10 villains and heroes, and that's unheard of. I feel very indebted to Jim Cameron for creating this character and movies. And I'm so happy that he's part of this one again. And that he and Linda came back... I think that you will all be surprised with this movie because it has come out unbelievable. I was blown away by it when I first saw it."
James Cameron, who directed the first two "Terminator" films, will serve as a producer on "Dark Fate".
Meanwhile, Hamilton told fans that playing Sarah Connor again brought back a lot of great memories.
"There was a world of richness that I could explore and then rock it at a certain age," the actress said. "The richness of my life experience will only enrich the character that I will play."
During the Comic-Con panel chat it was also revealed the new film will have an 'R' rating.