To be directed by James Ponsoldt, the film is the adaptation of Dave Eggers novel.
Tackling privacy in the digital age, the story is about a young woman (Watson), who is rising through the ranks of the Circle, a tech conglomerate.
Coltrane, 21, will play Watson's ex-boyfriend, who tries to go off the grid, under the radar of the Circle's technology, said The Hollywood Reporter.
The cast already includes John Boyega, Karen Gillan and Patton Oswalt.
Hanks, who plays one of the founders of the company, is producing the film under his Playtone production banner with his partner Gary Goetzman.