After spending some time in Paris, popular American dancer Guy Holden (Astaire) and his best friend, English lawyer Egbert Fitzgerald (Horton), land in London. While waiting at the London docks, Guy sees pretty American Mimi Glossop (Rogers) struggling with her dress, which is snagged in a trunk belonging to her aunt Hortense Ditherwell (Brady). Smitten, Guy offers his help, but in his haste to free Mimi, he pulls too hard and splits the back of the dress. Although furious at Guy, Mimi accepts his coat and calling card, then storms away without revealing her name or address.
Mimi returns the coat anonymously through a hotel bellboy, further frustrating Guy and inspiring him to sing "A Needle in a Haystack" about his determination to find her again. The desperate Guy drives the streets of London in search of Mimi and finally by chance crashes into the back of her car. Mimi takes off, but Guy pursues and eventually corners her in a park. After he proposes to her, Mimi tells Guy she cannot see him again, but she does at least give him her name.
Later, Hortense, who was once engaged to Egbert, brings the unhappily married Mimi to his office to discuss divorce proceedings. On learning that Mimi's neglectful husband Cyril, an English geologist, has refused to grant her a divorce, Egbert advises her to hire a professional co-respondentnote . Unaware that Mimi is the object of Guy's obsession, Egbert then convinces his lovesick friend to accompany him to a seaside resort, where the co-respondent is to rendezvous with Mimi.
At the hotel, Mimi finally starts to warm up to Guy after he dances with her to "Night and Day," but then due to a mix-up with the password, she mistakes him for the co-respondent. He is understandably confused when she first invites him to her hotel room and then treats him coldly once he gets there. Meanwhile, the real co-respondent—a cheerful, dandified Italian named Rodolfo Tonetti—searches the hotel for his liaison, giving increasingly mangled versions of the password to every woman he meets.
This confusion is eventually sorted out, and Egbert and Hortense then rush back to London to secure the needed detectives. Defying Tonetti's orders to stay in the room, Mimi and Guy sneak off, using the shadows of paper dolls to make him believe that they are still there, and pursue their romance on the hotel dance floor. The ensuing dance number, "The Continental," was at the time the longest musical sequence on film at seventeen and a half minutes.
The next morning, Hortense and Egbert, having been unable to find detectives, bring Cyril himself to the hotel. Although at first defiant and unyielding, Cyril gives in to Mimi's divorce demands when a hotel waiter unwittingly reveals to the group that he had met Cyril under a different name and with a different "wife" in tow. While Mimi and Guy celebrate her impending freedom, Hortense and Egbert announce that they were married on the way back from London.
The Gay Divorcee contains examples of:
- Adaptation Name Change: In the stage show, Guy's friend was named Teddy Egbert. In the movie, he's Egbert Fitzgerald.
- Anywhere but Their Lips: The lyrics of "The Continental" call for the dancers to kiss, as demonstrated by dozens of chorus members. When Guy and Mimi reach this point in their dance, he kisses her hand instead.
- Beta Couple: Hortense's determined pursuit of the reluctant Egbert mirrors Guy's pursuit of the reluctant Mimi.
- Brief Accent Imitation: After Guy has persuaded Mimi to take his phone number, another car tries to get through the roadblock he has set up. When the (British) driver asks if they can get through, Guy imitates his accent as he answers, "Oh, rather. Right you are. Cheerio."
- Busby Berkeley Number: "The Continental."
- Crash-Into Hello: Guy and Mimi's second meeting (with cars).
- Crazy-Prepared: Guy drives around with a folding "Road Closed" sign just in case he needs to cut off Mimi's path of escape. Sure enough, it comes in handy when she tries to drive away from him.Guy: [as he folds up the sign to allow another driver to pass] I got this at the sporting-goods store.
- Dance of Romance: "Night and Day" serves as this for Mimi. Also a Mating Dance thanks to the intensity of the mood.
- The Dandy: Tonetti.
- The Ditz: Hortense cannot properly remember the answer to any question asked of her or anything she needs to tell Egbert or Mimi, but has such a force of personality that she leaves other characters dizzy trying to keep up with her.
- Does This Remind You of Anything?: At the end of "Night and Day," while Mimi is still dazed from the Mating Dance she's just been through, Guy offers her a cigarette.
- Dogged Nice Guy: Guy (although a character who tried that "Road Closed" trick today would probably be called a Stalker with a Crush).
- Funny Foreigner: Tonetti.
- Gold Digger: Cyril appears to be a male example, since Mimi says she only sees him when he wants money. This is presumably why he refuses to divorce her, as well.
- Have a Gay Old Time:
- The title uses "gay" in the sense of "happy."
- In "Night and Day," which ends with the lines below, "making love" to someone meant "wooing":And my torment won't be through
Till you let me spend the rest of my life making love to you
Day and night, night and day!
- Heads or Tails?: When Guy arrives at Mimi's hotel suite, he flips a coin, apparently deciding whether to leave or stay. He doesn't like the answer, so he flips it again and stays.
- Irrelevant Act Opener: The opening sequence at the restaurant in Paris mainly serves as an excuse for some singing and dancing. The second "act" starts at the hotel, where a random cute girl (teenage Betty Grable) sings a Silly Song to Egbert called "Let's K-nock K-nees," which doesn't have much to do with anything.
- The Last of These Is Not Like the Others: When Guy finally catches up with Mimi in the park, he pulls out a picnic basket and props it on the running board of her car.Guy: Can I offer you anything? Frosted chocolate? Cointreau? Benedictine? Marriage?
Mimi: What was that last one?
Mimi: No, the one after that.
Guy: Oh, marriage?
- Latin Lover: Both invoked and amusingly subverted with Tonetti. Although he makes a living as "the lover" in divorce cases, he's actually a devoted family man whose motto is "Your wife is safe with Tonetti—he prefers spaghetti!"
- Literal Metaphor: The title of "Let's K-nock K-nees" appears to be a sexual innuendo, as the song is filled with them. In the ensuing dance number, Egbert, the singer, and the chorus members repeatedly tap their knees against their partners'.
- Long List: At the hotel, Egbert calls over a waiter and then forgets what he was about to order. The waiter runs through a list of every possible menu item he can think of before Egbert remembers that he just wanted tea.
- Love at First Sight: Guy for Mimi.
- Malaproper: Tonetti when he attempts to render his code phrase. "Chance is the fool's name for fate" goes through several versions, including "Chances are fate is foolish" and "Fate is a foolish thing to take chances with."
- Meet Cute: Guy, Mimi, the trunk, and the torn dress.
- Mistaken Identity: Mimi's confusion about who her co-respondent is.
- No Guy Wants to Be Chased: Egbert previously got away from Hortense's pursuit by claiming he had to go on an elephant hunt in India.
- One Dialogue, Two Conversations: Mimi and Guy discuss his profession a couple of times. All his answers could apply equally to a dancer or a gigolo.Mimi: Don't think you fooled me for a moment. I knew what you were all along. I knew how you made your living.
Guy: Oh, I'll admit I'm not proud of it, but I hope to do better someday. And in the meantime it does bring me in a decent income.
Mimi: Some people will do anything for money.
Guy: It's not as bad as all that. After all, I bring pleasure to thousands of people.
Guy: Yes, tens of thousands. I bring romance to tens of thousands of shop girls, servant girls, stenographers...
- Pedal-to-the-Metal Shot: Dogged Nice Guy Guy Holden pursues his love interest Mimi in what amounts to a vehicular chase. As soon as she leaves London traffic and enters a forested area, Mimi stomps the accelerator to get away from Guy.
- Pimped-Out Dress: Mimi gets several, but her two dancing dresses deserve special mention—a foamy, ruffled number for "Night and Day" and another with a dramatically dyed skirt for "The Continental." Even her negligee is pimped out with ruffles and a sash (see picture).
- Poirot Speak: Tonetti.
- Serenade Your Lover: "Night and Day" is one heck of a serenade song.
- Serial Spouse: Hortense has been married three times and is looking to make Egbert her fourth. (He was supposed to be her second, and ran away on an "elephant hunt" to escape her.)Hortense: Let's see, I didn't marry in 1929 or '30. That was the year of the crash, and men didn't know whether they had money or not.
- Silly Song: "Let's K-nock K-nees." Straitlaced lawyer Egbert is drawn into a dance number with a random girl at the beach resort.
- Stealth Insult:Tonetti: At home, my wife, he do not like me to sing.
Egbert: Unquestionably a woman of great perspicacity.
Tonetti: Oh, si, si, signor, you bet!
- Super Gullible: When Tonetti calls his wife from the hotel, he hears a man's voice in the background. His wife tells him that their nine-year-old son's voice is already changing. Tonetti believes it and is delighted.
- Teacher/Student Romance: How Mimi met Cyril—he was one of her instructors at school.
- Weird Trade Union: When Guy tries to take Tonetti's place (for free) as the co-respondent in Mimi's divorce case, Tonetti indignantly asks, "Are you a union man?" Guy and Mimi give him identical looks of disbelief.
- "Well Done, Son!" Guy: Egbert is thrilled that his father left him in charge of the law office. Despite strict instructions not to do anything, he's determined to handle Mimi's divorce successfully.
- Work Off the Debt: In the opening scene, Guy and Egbert are threatened with having to wash dishes at a Paris restaurant when they both forget their wallets. Guy eventually agrees to dance for his supper, only for Egbert to find his wallet after all just as the number finishes.
- Your Cheating Heart: In order to get a divorce from Cyril, Mimi needs evidence of adultery—hers or his. (See also Super Gullible above.)