Dancing and Irving Berlin's songs highlight this romantic comedy in which she thinks he is married to her friend when he really is someone else.
Producer Horace Hardwick (Edward Everett Horton) invites dancer Jerry Travers (Fred Astaire) to stay in his hotel room. Horace thinks Jerry should have a wife, but Jerry sings "Fancy Free" and tap dances. In the room below Dale Tremont (Ginger Rogers) wakes up and calls the manager. Horace goes down while she comes up. Jerry apologizes for his dancing affliction. Dale goes back to bed, and Jerry brings on sleep by dancing on sand. Jerry sends flowers to Dale and drives a horse cab for her. She rides a horse; when it rains, she stops at a bandstand. Jerry arrives with the cab. He sings "Isn't This a Lovely Day," and they dance.
Alberto Beddini (Erik Rhodes), who provides clothes for Dale, complains to her about the flowers. She thinks Jerry is Horace, who is married to her friend Madge. Dale slaps Jerry for being romantic and tells Alberto she hates men. Horace tells his butler Bates (Eric Blore) to find out about Dale. She leaves with Alberto, and Bates follows. In Horace's show Jerry sings "Top Hat" and dances.
In Venice Dale finds Madge Hardwick (Helen Broderick), who asks about her husband. Dale says he chased her. Jerry gets Horace to charter a plane. Horace tells Jerry he let Violet kiss him. Jerry sees Dale, who runs away. Madge puts Jerry with Horace in the bridal suite. Alberto warns Horace, and Horace tells Madge he hasn't met Dale. Madge tells Dale her husband lied. Dale calls on Jerry to scare him, kissing him and saying they met in Paris. Jerry goes along, and Dale runs out. Jerry joins Dale and Madge, saying Madge is understanding of the women he likes. Jerry dances with Dale and sings "Cheek to Cheek." Dale says she knows who Jerry is. When Jerry asks her to marry, she slaps him again. Dale tells Madge that her husband wants a divorce so he can marry her. Horace gets a black eye from Madge.
Dale quickly marries Alberto, and Jerry and Horace are asked to give up the bridal suite. Dale calls Madge, and Jerry realizes that Dale mistook him for Horace. Alberto and Jerry both claim the bridal suite. Jerry goes to the room above and dances on the floor. Dale sends Alberto to make him stop. Horace replaces Jerry dancing and is threatened by a sword-wielding Alberto until he learns Horace is the wrong man. Jerry goes down to Dale and in a gondola explains. Bates sends Alberto, Horace, and Madge out in a boat without gas, enabling Jerry and Dale to come back and have dinner. Dale sings "The Piccolino," and they dance again. Finally everyone meets in the bridal suite, and Bates says he imitated a priest; so Alberto and Dale are not really married. In the final scene Jerry and Dale dance.
This sophisticated entertainment appeals to romantic desires, using a misunderstanding to provide comic irony and obstacles for love to overcome.