Her death Tuesday was confirmed by The Walt Disney Co. The cause was complications from a fall, according to the Los Angeles Times.
Miller, the eldest daughter of Walt and Lillian Disney, was born Dec. 18, 1933.
She played a key role in the completion of the Frank Gehry-designed Walt Disney Concert Hall in Los Angeles, bucking city leaders who wanted to remove Gehry from the project.
She also founded the Walt Disney Family Museum, which opened in 2009 in San Francisco's Presidio, as a tribute to her family's legacy.
She is survived by her husband, Ronald, and seven children.