The iconic actress had already completed filming her role as General Leia Organa in the upcoming film before she passed away. Iger revealed at an event at the University of Southern California on Thursday that there would be no changes because of her death.
"She appears throughout [Episode ] VIII, and what I can say about that is, she is in VIII, and we're not changing VIII to deal with her passing," he said. "Her performance, which we're really pleased with, remains as it was in VIII."
Fisher will be honored along with her mother, Debbie Reynolds, at a public memorial event on Saturday in Los Angeles. Both passed away in December 2016.
Though they have the technological ability to digitally recreate actors who have passed away, Iger said they would not be doing that for Carrie Fisher in The Last Jedi.
Iger said he'd already seen the sequel to Star Wars: The Force Awakens, mentioning that it was "quite good."
"VIII is, I think, just as satisfying as VII was. We're really proud of it," he said. "It's a combination of drawing from the great heritage that was George Lucas' Star Wars, but also bringing it to new places with new characters."
That's not the only Star Wars news Iger revealed during the event. He teased the plot of the upcoming to-be-titled stand-alone Han Solo film, saying we will learn how Han Solo got his name. He said it would involve "acquiring a certain vehicle and meeting a certain Wookiee."
Those upcoming projects are just the beginning, he teased. He said they have a creative team planning out the next 15 years of the franchise.
The Walt Disney Company is the parent company of Lucasfilm and this station.