Rich Ross, 50, took the job two and a half years ago with a mission to cut costs and develop new hits. But the studio's losses continued under Ross despite major restructuring efforts.
In March, Disney booked a $200 million loss on "John Carter," a special-effects-laden movie based on the Edgar Rice Burroughs book series. The movie starring Taylor Kitsch had an estimated budget of $250 million, matching what 20th Century Fox spent on "Avatar."
"John Carter" made only $269 million at box offices worldwide while "Avatar" took in $2.8 billion After splits with theater owners and marketing expenses, Disney said "John Carter" would cause a studio-wide loss of $80 million to $120 million in the quarter through March.
In a memo to staff on Friday, Ross said that the chairman's role at Walt Disney Studios was no longer right for him.
In his previous role, Ross brought "High School Musical" and "Hannah Montana" to TV audiences as the former head of Disney Channels Worldwide.
The Walt Disney Co. CEO Bob Iger wished Ross well in a statement.
"Rich Ross's creative instincts, business acumen and personal integrity have driven results in key businesses for Disney," Iger said. "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."
Disney has not named a successor.
Disney is the parent company of ABC7.