Cage and Polanski will also be joined by fellow Oscar winner Tilda Swinton.
According to Variety, production on "The Ghost" will begin in September with Cage playing a ghostwriter working on the memoirs of England's former prime minister. The secrets he uncovers may have something to do with why a former ghostwriter turned up dead.
Brosnan will play the prime minister, while Swinton will play the his wife, who begins to fall for the ghostwriter.
Polanski and Harris wrote the script together.
Last seen in "Ghost Rider," "Next" and "National Treasure: Book of Secrets," "Cage" has "Bangkok Dangerous" set for release later this year.
Swinton, who picked up her Oscar earlier this year for "Michael Clayton," has a pair of high profile late-2008 releases with "Burn After Reading" and "The Curious Case of Benjamin Button."
Swinton and Cage previously teamed up for "Adaptation."
While he's best know for his work in the James Bond franchise, Brosnan will show a very different side of himself later this summer in the musical comedy "Mama Mia!"