The co-founder of New York's Circle in the Square Theatre passed away of complications from pneumonia.
Mann directed more than 200 stage productions, including Vanessa Redgrave's Broadway debut in The Lady from the Sea and Salome starring Al Pacino.
In 1951, he started up the Circle in the Square Theatre School, a non-profit acting and music training centre which counts Philip Seymour Hoffman, Kevin Bacon, Dustin Hoffman, Lady Gaga and Benicio Del Toro as former pupils.
He scored his first Tony in 1957 for Long Day's Journey into Night and accepted a special Tony in 1976 for his work with Circle in the Square.
The Broadway League's Executive Director Charlotte St. Martin says, "His contributions to Broadway and off-Broadway are immeasurable, both in the productions he created and the talent that he nurtured. He will be missed by many in our community, and our hearts go out to his friends, family, and students."