Michael Gough got his part (Dighton, the first murderer) by making a fuss to his fellow actor friends about only established stars getting cameo parts and leaving nothing for struggling actors like him. One night he got a phone call, and a voice said "You've been stirring it, haven't you? Right little shit." Gough demanded to know, "Who is this?" only to be stunned by the response, "It's Larry", which of course was Sir Laurence Olivier. Olivier was just having some fun at Gough's expense, had taken on-board his criticisms and was ringing to offer him the part of one of the murderers in this movie. When asked which one he wanted to play, Gough quickly said "Whichever one has the most lines", and he got his wish. Olivier arranged matters so that Gough's scenes were split over several days, instead of all being done in one day, so that Gough would maximize his per diem fee.

Sir Laurence Olivier used long takes throughout this movie to allow the actors and actresses to build their scenes more theatrically. His opening soliloquy was shot in one nine-minute take. When he almost dropped the King's crown in the first scene, rather than re-shoot, he used the accident to create a motif for the movie.

The first movie to have its U.S. premiere in theaters and on television simultaneously. This occurred on the afternoon of 11 March 1956, when NBC broadcast it on the same day it had its U.S. premiere in New York City. (It had already had its world premiere and first run in London in 1955.) The telecast was the longest single presentation of a movie or play (three hours counting the commercials) ever shown on television up to that time. Classic British films presented by J. Arthur Rank, such as Caesar and Cleopatra (1945), had already made their network television debuts on an ABC program titled "Famous Film Festival", but many of these were either drastically cut to fit a ninety-minute time slot or shown in two parts. Walt Disney had already begun, on his The Magical World of Disney (1954) television program, to telecast some of his theatrical movies, but these were shown in two or more one-hour segments, one segment per week, or edited down to one hour, as in the case of Alice in Wonderland (1951). It was not until CBS showed The Wizard of Oz (1939) in 1956, that an uncut, full-length theatrical movie was shown on network television during prime time in one evening.

The failure of this movie to earn a profit in the U.S. during its theatrical release, together with the untimely death of Alexander Korda, who had backed the production of this movie, effectively ended Laurence Olivier's dream of filming William Shakespeare as a director. He is accorded the honor of being the greatest Macbeth of the 20th century, but he could never raise the financing to make the movie after the financial failure of this one. Mike Todd expressed interest in financing an Olivier version of "Macbeth", but Todd was killed in a plane crash before those ideas could come to fruition. Olivier never again directed a Shakespearean movie, possibly the result of the fabled actors' curse attached to "The Scottish Play".

Sir Laurence Olivier claimed in his 1982 book "On Acting" that he had wanted to cast Orson Welles in the role of the Duke of Buckingham, but life-long friend (and rival) Sir Ralph Richardson had wanted the role, and Olivier gave it to him. In this book, Olivier claimed to wish that he had disappointed Richardson and cast Welles instead, as he would have brought a greater sense of "oiliness" and cunning to the part that would have gone well with the plot element of conspiracy. All this is highly unlikely to be true, of course - it is extremely improbable that Welles, who made several important Shakespeare films of his own, would have played a subordinate role under Olivier's direction (just as Olivier refused to take direction from Welles when the latter directed him on stage in "Rhinoceros" in 1960), and Richardson received rave reviews for his performance - including many which suggested that he had out-acted Olivier. This would almost certainly have greatly annoyed Sir Laurence, even more than 25 years later, and his disparaging remarks about Richardson may simply have been petty jealousy.