The novel about a former British prime minister was published by Hutchinson last month.
Harris and Polanski are penning the screenplay for the film, which is slated to begin shooting next year.
"I have been looking for a political thriller to direct for some time, and 'The Ghost' could not be more perfect," Polanski said in a statement. "Robert has constructed a novel with such suspense, it is hard to put down."
"Roman Polanski is a terrific director of tense thrillers, and I couldn't imagine a better person to make a movie out of 'The Ghost,'" said Harris. "There's a lot of psychological intrigue in the story, as well as espionage and politics, and most of the action takes place in an ocean-front house during the middle of winter -- all of it classic Polanski territory. I am thrilled to be working with him on the screenplay."
Polanski and Harris also worked together on a script based on Harris' novel, "Pompeii."
Production on the film was postponed, however, due to the threat of a possible Screen Actors Guild strike in June.