Judy Holliday turned down the role of Lorelei Lee because she felt no actress other than Carol Channing (who played the part on Broadway) should be cast.
Marilyn Monroe kept insisting on retakes despite approval of takes by director Howard Hawks. When Fox asked Hawks how production could be sped up he retorted: "three wonderful ideas: Replace Marilyn, rewrite the script and make it shorter, and get a new director."
Marilyn Monroe reportedly suggested the line "I can be smart when it's important, but most men don't like it."
A song written for Marilyn Monroe to perform in this picture, "Down Boy" (music by Hoagy Carmichael, lyrics by Harold Adamson), was rejected, but later sung and danced by Betty Grable in Three for the Show.
According to Marni Nixon, the studio initially wanted Marilyn Monroe's entire voice dubbed, as they thought her voice was silly. Nixon thought that was "awful", as she felt Monroe's voice suited her persona so beautifully. Nixon told The New York Times in March 2007 that she ended up only dubbing the operatic "no, no, nos" at the beginning of the song.
At least one other number was shot, then cut. In the original theatrical trailer, Jane Russell and Marilyn Monroe were shown among dancers, climbing the steps of a slide in a children's playground. The song was a French version of "Two Little Girls from Little Rock". Marilyn and Jane wear the costumes when Tommy Noonan corners them backstage in the French nightclub.
For this film Gwen Verdon coached stars Jane Russell and Marilyn Monroe in both their dance and walk - Monroe with less sex, Russell with more. It's rumored that at one point in the film, Verdon dubs both Monroe's and Russell's swaying bottoms.
In her very last interview, (10 years after making "Gentlemen Prefer Blondes,") Marilyn Monroe recalls the lack of respect studio execs had for her, but makes a point of mentioning co-star, Jane Russell: "I remember when I got the part in Gentlemen Prefer Blondes. Jane Russell, she was the brunette in it and I was the blond. She got $200,000 for it, and I got my $500 a week, but that to me was, you know, considerable. She by the way, was quite wonderful to me."
In the "Ain't There Anyone Here for Love?" sequence, Jane Russell's fall into the pool was an accident. When Howard Hawks saw the dailies, he kept it in the film.
Originally bought by Fox as a vehicle for Betty Grable. After the success of Niagara (which featured Marilyn Monroe), however, the studio believed they had a more potent and far less expensive sex symbol than Grable (who was earning around $150,000 per picture vs. Monroe's $18,000).
The "Diamonds Are A Girl's Best Friend" number was later re-shot in CinemaScope, to be used as part of a CinemaScope demonstration held on the Fox lot in March of 1953. Producer Darryl F. Zanuck told "Daily Variety" that it only took 3-1/2 hours to shoot the number in CinemaScope versus four days for the original film version. The public finally saw the CinemaScope version ten years later when it closed Fox's documentary tribute to MM, Marilyn,
The play "Gentlemen Prefer Blondes" opened at the Ziegfeld Theater on December 8, 1949 and ran for 740 performances starring Carol Channing. The original play of the same name opened in 1928 and ran 128 performances.
The ship model shown is the one used previously in Titanic and was refurbished to resemble the SS Ile de France, which is clearly named in the film. The model (2009) resides in a Marine Museum in Falls River, Massachusetts. Some of the ocean liner sets used were also left over from "Titanic".
The story was based on an ocean voyage to Europe that Anita Loos took on the same boat taking the US Olympic Team. Whichever ship she actually took, the liner that is mentioned in this film was the SS Ile de France. The famous liner was actually used in the film The Last Voyage, but it has a more heroic place in history. It was the SS Ile de France that played a major role in the rescue of the passengers from the Italian liner Andrea Dorea in 1956, after the latter ship collided with the Swedish ship Stockholm off the coast of Nantucket, Massachusetts. The SS Ile de France was decommissioned shortly before the filming of "The Last Voyage," in which she was partially sunk for several key scenes. When filming was completed, she was towed to the scrap docks.
The teaming of Jane Russell and Marilyn Monroe proved to be so successful, critically and commercially, that Fox wanted to re-team the duo. A December 1954 item in the Hollywood Reporter's "Rambling Reporter" column indicated that the studio wanted Russell and Monroe to star in the film How to Be Very, Very Popular. Monroe passed on the project because she didn't like the script. In January 1955, the studio cast Sheree North as Curly (the part intended for Monroe) and Betty Grable as "Stormy Tornado" (originally intended for Russell).
This was Jane Russell's only film with Marilyn Monroe. They got along well. Russell called Monroe "Blondie" and was often the only person on the set who could coax Monroe out of her trailer to begin the day's filming.
When told she was not the star of the film, Marilyn Monroe was quoted: "Well whatever I am, I'm still the blonde."