By Agence France-Presse
Trade press and websites had been speculating that Trevorrow, 40, was going to leave the blockbuster since the opening of his critically-panned commercial flop "The Book of Henry."
"Lucasfilm and Colin Trevorrow have mutually chosen to part ways on 'Star Wars: Episode IX,'" Lucasfilm said in a statement.
"Colin has been a wonderful collaborator throughout the development process, but we have all come to the conclusion that our visions for the project differ. We wish Colin the best and will be sharing more information about the film soon."
The Hollywood Reporter, citing unnamed sources, said the main point of contention was ongoing "script issues," with Trevorrow being forced into several rewrites.
The weekly trade paper reported that the relationship between Trevorrow and Lucasfilm chief Kathleen Kennedy had become "unmanageable," although it added that she had tried to avoid losing another director.
In June, Lucasfilm sacked directing duo Phil Lord and Chris Miller ("21 Jump Street," "The Lego Movie"), who were just weeks away from wrapping principal photography on the hotly-anticipated Han Solo spinoff.
The pair were replaced by Oscar-winning filmmaker Ron Howard after clashing with Kennedy and writer Lawrence Kasdan, according to reports.
Trevorrow's departure will be seen as an equally huge upheaval as he is considered hot property after scoring big with Universal's creature feature "Jurassic World" (2015), the fourth-highest grossing movie of all time.
The untitled Han Solo movie is due out on May 25 next year, while production has yet to start on "Star Wars: Episode IX," slated for release 12 months later.
"The Last Jedi," the next film in the "Star Wars" franchise, directed by Rian Johnson, opens on December 15.