Jacques Bergerac, who plays the skating instructor Sandomir, did not know how to skate.

Leslie Caron, Louis Jourdan and Maurice Chevalier are all French, just like the characters they play (Gigi, Gaston, Honore Lachaille).

Leslie Caron's singing voice was dubbed by Betty Wand. However, original demo recordings of Caron singing "The Night They Invented Champagne" and ""Say A Prayer for Me Tonight" were retained, and have been released on CD.

Ina Claire was offered the role of Aunt Alicia but declined.

Dirk Bogarde was considered for the role of Gaston and expressed interest, but he was unable to commit due to his having a contract with producer J. Arthur Rank.

Alan Jay Lerner and Frederick Loewe's 'My Fair Lady' had just opened on Broadway. Its sets and costumes were lavishly praised so Alan Jay Lerner insisted the play's production designer, Cecil Beaton, should be employed on the film.

Alan Jay Lerner's usual collaborator, Frederick Loewe, hated working for Hollywood and had vowed not to work on another movie. However, he was sufficiently charmed by the original novel to renege on that promise, albeit under the condition that it be made in France.

Cecil Beaton had to supply over 150 period costumes for the scene in the Bois, and 20 ornate gowns for the scene in Maxims. Beaton had difficulty procuring such a large amount of costumes in Paris but when the production moved to Hollywood, he found warehouses stuffed to bursting with period furniture and costumes.

According to Vincente Minnelli, when shooting in the French restaurant Maxim's the film crew the restaurant's famous mirrored walls to be covered up because they would reflect the equipment, but Minnelli contended that they had to be seen (and uncovered) as they were the hallmark of Maxim's. Eventually cinematographer Joseph Ruttenberg resolved the matter satisfactorily, by putting suction cups on photo flood lights.

After Alan Jay Lerner and Frederick Loewe had composed a few songs, they took them to Maurice Chevalier who loved them and immediately agreed to star in the film.

By mid-July 1957, the songwriters had still not come up with the title song. One evening, Frederick Loewe was at a piano while Alan Jay Lerner was indisposed in the bathroom, and when Loewe began playing a particular melody, he later recalled Lerner jumped up, "his trousers still clinging to his ankles, and made his way to the living room. 'Play that again,' he said." That melody ended up as the film's title song.

Even though several other musicals had been produced at MGM into the 1960's, Gigi is often referred to as the studio's last traditional musical, since this motion picture was the final musical production to be filmed under the auspices of the studio's Arthur Freed Unit, which had been responsible for all of MGM's classic movie musicals throughout Hollywood's Golden Era.

From 1954-56, Arthur Freed had to battle the Hays Code in order to bring Colette's tale of a courtesan-in-training to the cinema. He eventually convinced the film industry's Code Office to view the story as condemning rather than glorifying a system of mistresses.

Gaston's butler Henri (played by Fran├žois Valorbe) and chauffeur Pierre (played by Roger Saget) were both dubbed by Paul Frees.

Gaston's walk through Paris while singing "Gigi" uses camera magic to make parts of Paris which are miles apart seem adjacent to each other. This technique, called "creative geography", was created and named by French filmmaker Jean Cocteau.

Most of the film was shot on location in Paris, with the last few numbers being completed in an apartment that MGM constructed on their backlot.

The biggest money-maker for Vincente Minnelli from his years at MGM.

The Broadway production of the stage play "Gigi" by Anita Loos opened at the Fulton Theater on November 24, 1951, ran for 219 performances and closed on May 31, 1952. The title role was portrayed by then unknown Audrey Hepburn who won the 1952 Theatre World Award for her performance.

The cast had to mouth the songs as production was so swift that the score had yet to recorded by the time it came to filming.

The cat in the movie reacted violently whenever it was in a scene with Leslie Caron, but director Vincente Minnelli insisted on having that particular cat, so it had to be heavily drugged. This is especially obvious during "Say a Prayer for Me Tonight".