James Cagney was originally offered the role of Alfred Doolittle. When he pulled out at the last minute, it went to the man who played it on Broadway, Stanley Holloway. Peter O'Toole, Cary Grant, Noel Coward, Michael Redgrave and George Sanders were all considered for the role of Higgins before Rex Harrison was finally chosen to reprise his Broadway role.
Jack L. Warner considered this film one of his finest achievements.
Jack L. Warner originally didn't want Rex Harrison to reprise his stage role as Higgins for the film version, since he had seen Cleopatra and thought the actor looked too old to be believable as Audrey Hepburn's love interest. Peter O'Toole was considered for the role of Professor Higgins, but his salary demands were too high. Harrison responded in a letter to Warner that he had only looked old as Gaius Julius Caesar because he had been playing an epileptic at the end of his life, and after sending some publicity photographs of himself - minus his toupee - he was eventually cast.
Jack L. Warner paid $5.5 million for the film rights in February 1962. This would set a record for the amount of money paid for the film rights to any intellectual property, broken only in 1978 when Columbia paid $9.5 million for the film rights to Annie
27A Wimpole Street in London (Higgins' address) does not exist (there is a 27 Wimpole Street).
About twenty minutes before the end of the film, Colonel Pickering offers to go off and find the missing Eliza. He exits the library set - and is never seen in the movie again!
According to actress Nancy Olson, who was married to lyricist Alan Jay Lerner at the time he was writing the musical, Lerner and Frederick Loewe had the most trouble writing the final song for Henry Higgins. The two writers had based the whole concept of the musical around the notion that Higgins was far too intellectual a character to emotionally sing outright, but should speak his songs on pitch, more as an expression of ideas. However, both composer and lyricist knew that Higgins would need a love song towards the end of the story when Eliza has abandoned him. This presented an obvious problem: how to write an emotional song for an emotionless character. Lerner suffered bouts of insomnia trying to write the lyrics. One night, Olson claims, she brought him a cup of tea to soothe his nerves. As she entered his study, Lerner thanked her and said "I guess I've grown accustomed to you...I've grown accustomed to your face." According to Olson, his eyes suddenly lit up, and she sat down and watched him write the entire song in one sitting, based on the idea that although Higgins couldn't "love" Eliza in the traditional sense, he would surely notice the value she represented as part of his life.
According to one of Rex Harrison's biographers, Alexander Walker, the song "I've Grown Accustomed to Her Face" held special memories for the actor, as during the original Broadway run he used to sing the song to his third wife Kay Kendall, who would stand in the wings watching his performance. Harrison later admitted that when he sang the song in the film he was thinking all the time about Kendall, who had died a few years before from leukemia.
Although Rex Harrison was desperate to be cast as Professor Higgins, he refused to do a screen test since he felt this was beneath his dignity. He did, however, promise to Jack L. Warner that he would not simply repeat his stage performance, but would instead adapt his performance accordingly for the film.
Although her singing was dubbed by Marni Nixon, Audrey Hepburn's singing does actually appear in the form of the first verse of "Just You Wait, Henry Higgins". However, when the song heads into the soprano range (76 seconds in), Nixon takes over vocals. Hepburn sings the last 30 seconds of the song as well as the brief reprise. She also sings the sing-talking parts for "The Rain in Spain". Overall, as Hepburn reportedly said, about 90% of her singing was dubbed. That was far more than what she expected, as she was initially promised that most of her vocals would be used. According to Nixon, Hepburn was upset that she could not play the role vocally, and always blamed herself for that.
Although most of the art direction and costume designing credit went to Cecil Beaton, art director Gene Allen would later go on record to say that Beaton only designed the women's clothes and had no part in the actual designs of the sets, though he insisted on taking the credit for them. In fact, Beaton had it written into his contract that he receive sole credit for production designer.
Although playing a 19-year-old, Audrey Hepburn was actually 35 in real life. Jeremy Brett was cast as 20-year-old Freddie so Hepburn would not seem too old in comparison.
Amusement park trams were rented to carry ballroom scene extras across the studio lot, in order to prevent their makeup and costumes from getting dirty or damaged.
An entire sound stage was used for doing hair and makeup for the Ascot race scene.
Apparently, Shirley Jones was one of the actresses to whom Jack L. Warner planned to offer the role of Eliza Dolittle if Audrey Hepburn turned it down.
At $17 million, this was the most expensive Warner Brothers film produced at the time. Nevertheless, it went on to become one of the biggest grossing films of 1964.
Audrey Hepburn apparently believed that Julie Andrews should have played Eliza Doolittle in the film, but was told by Jack L. Warner that Julie wouldn't be cast even if Audrey turned the role down.
'Julie Andrews' said that she "threw a few tantrums" when she learned that she wouldn't be playing Eliza in the film, and yet, she got along very well with Audrey Hepburn, without holding a grudge against Audrey whom she knew was an innocent party in the whole thing.
Average Shot Length = 10 seconds
Because of the way Rex Harrison talked his way through the musical numbers, they were unable to prerecord them and have him lip-sync, so a wireless microphone (one of the first ever developed) was rigged up and hidden under his tie. However, this meant that his mouth and words were completely in sync and everyone else's looked off, since they were lip-syncing (when everyone is lip-syncing, it's not that noticeable). The studio thought that this was too obvious so they altered Harrison's soundtrack, lengthening and shortening notes in various places so that his synchronicity is slightly off like all the other actors.