Charlton Heston lobbied heavily for the role of Thomas More, but was never seriously considered by the producers as a candidate for the role. Heston would go on to play More in several stage productions of the play and ultimately film a television production of it in 1988.
Robert Bolt offered the part of Norfolk to his friend, American actor-director John Huston. Huston turned it down.
Paul Scofield and Leo McKern reprised the roles they played in the Broadway production of the play. During most of the play's 20-month run, the role of Margaret was played by a young Faye Dunaway.
The original play opened at the ANTA Playhouse (New York) on November 21, 1961 and played for 637 performances starring Paul Scofield.
In the first (London) run of the play, Leo McKern played not Cromwell but the Common Man, a narrator-figure who addresses the audience and plays several characters in the story - More's servant Matthew, the man who rows him home, his jailer, etc. These characters also appear in the film, but are played by several actors. The original stage device of having them all played by the same actor was kept in the 1988 version. In the play, the lines stating what happened to the historical figures after More's death are spoken by the 'Common Man'; in the film, they are spoken in voice-over at the end by Colin Blakely, who plays Matthew.
One of only 4 productions to win both the Best Play Tony (1962) and the Best Picture Oscar (1966). The other 3 are My Fair Lady (1957/1964), The Sound of Music (1960/1965) and Amadeus (1981/1984).
Paul Scofield won the 1962 Tony Award (New York City) for Actor in a Drama for "A Man for All Seasons" and recreated his role in the filmed production.
According to Welles, he had Zinnemann removed from the set and directed his scenes himself.