Mitchell Kapner has been hired to write a script for the follow-up, which would continue the adventures of Oz, played by James Franco, reported Hollywood reporter.
With expectations of a box-office bonanza this weekend, Disney is hoping to make it into a franchise.
Kapner came up with the concept and ideas for the origin story of Oz, which is based on the classic L Frank Baum books. Kapner pitched the idea to producer Joe Roth, who set it up at Disney.
Kapner shares screenwriting credit with David Lindsay-Abaire, who came on board later in the process.
Before Oz, Kapner wrote "The Whole Nine Yards" and its sequel, "The Whole Ten Yards", and also worked on the action movie "Romeo Must Die".
Planning for sequels to tentpoles has become increasingly the norm in Hollywood, with movies ranging from "Snow White and Huntsman" to comedies such as the "Hangover" getting new additions.