'Edmund O'Brien''s movie debut.
Irving Thalberg first presented the project to Charles Laughton in 1934. But plans didn't materialize until Laughton signed with RKO and chose this film as his first assignment at that studio.
Charles Laughton's makeup took two-and-a-half hours to apply each day.
American Film Institute Catalog of Feature Films 1931-1939 includes Gail Patrick and Laura Hope Crews among the uncredited players, without role designations. Neither actress appears in the film in any role of prominence, which their status in the industry at that time would have dictated. It's possible, however, they participated anonymously as extras, just for the experience, as many of their contemporaries often did.
At a cost of $1.8 million, this was one of the most expensive films ever made by RKO Pictures. The Notre Dame replica alone cost $250,000.
Having worked with her in London, Charles Laughton insisted that 'Maureen O'Hara' would be the perfect Esmeralda for the film.
Pandro S. Berman offered Basil Rathbone a principal part in this film but Universal refused to release him.
RKO specifically wanted to outdo the 1923 silent version of the story, so a vigorous campaign that spared no expense was undertaken. Much attention was given to advance publicity; no pictures of Charles Laughton in full Quasimodo makeup and costume were allowed to be seen so that a first-time viewing would be a guaranteed shock. Also, the studio hired (at Laughton's request) leading makeup artist Perc Westmore to supervise makeup. Unfortunately, Westmore and Laughton had heated quarrels before a final image for Quasimodo was agreed upon.
Sound from King Kong is used in the film: when Esmeralda is being tortured, some of her screams we hear belong to Fay Wray. Also, when Quasimodo is defending the cathedral, some of the screams of the wounded attackers belong to the sailors from King Kong; and when Frollo falls to his death, his scream belongs to one of the sailors as well.
The film required the use of 2,500 wigs.
The only movie screened at the very first Cannes Film Festival (the remainder of the festival was canceled when Adolf Hitler's Nazi forces invaded Poland on 1 September 1939).
This was noted Shakespearean actor-manager Walter Hampden's first sound film.
This was RKO's last release for 1939 (and second costliest in its history, next to Gunga Din). Although it premiered about the same time as Gone with the Wind, it held its own at the box office, grossing an impressive $3.155 million.
Two actors in the film play two different roles, one credited, one not. Thomas Mitchell plays Clopin (credited) and also plays the deaf judge that sentences Quasimodo to the pillory. George Tobias plays the beggar who wants to hang Gringoire (credited as "Beggar"), and also plays one of the workmen in the cathedral who sees Quasimodo ringing the bells in his joy of Esmeralda.
Well aware of the war raging in Europe, Charles Laughton chose a lull in the day's shooting to recite, in full Quasimodo costume, Lincoln's Gettysburg Address, as he had done in the film Ruggles of Red Gap. As in the previous film, it stunned the cast and crew for the rest of the shooting day.