The movie mogul took over the top executive position two-and-a-half years ago.
The Disney veteran announced his departure to the studio in an email on Friday (20Apr12), stating, "I no longer believe the chairman role is the right professional fit for me."
Company chief executive Robert Iger handpicked Ross to turn around Disney's fortunes in October, 2009, but the outgoing chairman has faced a string of problems and film flops, including the recently released John Carter, which forced the firm to take an estimated $200 million (£125 million) hit.
Ross also tasted failure with Mars Needs Moms and Prom.
A statement from Iger reads, "I appreciate his countless contributions throughout his entire career at Disney, and expect he will have tremendous success in whatever he chooses to do next."
Before he became Disney chairman, Ross had success at the Disney Channel and is credited with greenlighting shows like Hannah Montana and High School Musical.