York died Saturday at the Royal Marsden Hospital in London. Her son, Orlando Wells, told the news agency she had entered the hospital Jan. 6 after experiencing shoulder pain.
In 1969, York was nominated for a Golden Globe and Academy Award for her performance in They Shoot Horses, Don't They?. She famously told the Academy she was offended to receive the nomination without being asked.
Her career faded, but she returned to play Superman's biological mother in the feature films that starred Christopher Reeve.
York spent her later career on the London stage and appeared on British TV series such as Holby City as recently as 2004. Her last film was The Calling, released last year in the United Kingdom.
She is survived by her children, Orlando and Sasha, and several grandchildren.